Set relations to retrieve by a query at compile time.
+ Add compile-time utility functions to build strings and queries. * Relations to retrieve when querying a model must now be set at comptime.
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GPG key ID:
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6 changed files with 148 additions and 137 deletions
33
src/comptime.zig
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33
src/comptime.zig
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@ -0,0 +1,33 @@
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/// Append an element to the given array at comptime.
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pub fn append(array: anytype, element: anytype) @TypeOf(array ++ .{element}) {
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return array ++ .{element};
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}
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/// Join strings into one, with the given separator in between.
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pub fn join(separator: []const u8, slices: []const[]const u8) []const u8 {
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if (slices.len == 0) return "";
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// Compute total length of the string to make.
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const totalLen = total: {
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// Compute separator length.
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var total = separator.len * (slices.len - 1);
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// Add length of all slices.
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for (slices) |slice| total += slice.len;
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break :total total;
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};
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var buffer: [totalLen]u8 = undefined;
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// Based on std.mem.joinMaybeZ implementation.
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@memcpy(buffer[0..slices[0].len], slices[0]);
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var buf_index: usize = slices[0].len;
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for (slices[1..]) |slice| {
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@memcpy(buffer[buf_index .. buf_index + separator.len], separator);
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buf_index += separator.len;
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@memcpy(buffer[buf_index .. buf_index + slice.len], slice);
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buf_index += slice.len;
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}
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return &buffer;
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}
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155
src/query.zig
155
src/query.zig
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@ -8,25 +8,71 @@ const _sql = @import("sql.zig");
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const _conditions = @import("conditions.zig");
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const relations = @import("relations.zig");
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const repository = @import("repository.zig");
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const InlineRelationsResult = struct {
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};
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const _comptime = @import("comptime.zig");
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/// Repository query configuration structure.
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pub const RepositoryQueryConfiguration = struct {
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select: ?_sql.RawQuery = null,
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join: ?_sql.RawQuery = null,
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where: ?_sql.RawQuery = null,
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with: ?[]const relations.Eager = null,
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};
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/// Compiled relations structure.
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const CompiledRelations = struct {
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inlineSelect: []const u8,
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inlineJoins: []const u8,
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};
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/// Repository models query manager.
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/// Manage query string build and its execution.
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pub fn RepositoryQuery(comptime Model: type, comptime TableShape: type, comptime repositoryConfig: repository.RepositoryConfiguration(Model, TableShape)) type {
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// Pre-compute SQL buffer size.
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pub fn RepositoryQuery(comptime Model: type, comptime TableShape: type, comptime repositoryConfig: repository.RepositoryConfiguration(Model, TableShape), comptime with: ?[]const relations.ModelRelation) type {
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const compiledRelations = comptime compile: {
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// Inline relations list.
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var inlineRelations: []relations.ModelRelation = &[0]relations.ModelRelation{};
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if (with) |_with| {
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// If there are relations to eager load, prepare their query.
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// Initialize inline select array.
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var inlineSelect: [][]const u8 = &[0][]const u8{};
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// Initialize inline joins array.
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var inlineJoins: [][]const u8 = &[0][]const u8{};
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for (_with) |relation| {
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// For each relation, determine if it's inline or not.
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var tt = relation.relation{};
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const relationInstance = tt.relation();
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if (relationInstance.inlineMapping()) {
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// Add the current relation to inline relations.
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inlineRelations = @ptrCast(@constCast(_comptime.append(inlineRelations, relation)));
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// Build table alias and fields prefix for the relation.
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const tableAlias = "relations." ++ relation.field;
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const fieldsPrefix = tableAlias ++ ".";
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// Generate selected columns for the relation.
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inlineSelect = @ptrCast(@constCast(_comptime.append(inlineSelect, relationInstance.genSelect(tableAlias, fieldsPrefix))));
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// Generate joined table for the relation.
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inlineJoins = @ptrCast(@constCast(_comptime.append(inlineJoins, relationInstance.genJoin(tableAlias))));
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}
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}
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break :compile CompiledRelations{
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.inlineSelect = if (inlineSelect.len > 0) ", " ++ _comptime.join(", ", inlineSelect) else "",
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.inlineJoins = if (inlineJoins.len > 0) " " ++ _comptime.join(" ", inlineJoins) else "",
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};
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} else {
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break :compile CompiledRelations{
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.inlineSelect = "",
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.inlineJoins = "",
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};
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}
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};
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// Pre-compute SQL buffer.
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const fromClause = " FROM \"" ++ repositoryConfig.table ++ "\"";
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const defaultSelectSql = "\"" ++ repositoryConfig.table ++ "\".*";
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const defaultSelectSql = "\"" ++ repositoryConfig.table ++ "\".*" ++ compiledRelations.inlineSelect;
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const defaultJoin = compiledRelations.inlineJoins;
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// Model key type.
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const KeyType = repository.ModelKeyType(Model, TableShape, repositoryConfig);
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@ -39,9 +85,6 @@ pub fn RepositoryQuery(comptime Model: type, comptime TableShape: type, comptime
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connection: *database.Connection = undefined,
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queryConfig: RepositoryQueryConfiguration,
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/// List of loaded inline relations.
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inlineRelations: []relations.Eager = undefined,
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query: ?_sql.RawQuery = null,
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sql: ?[]const u8 = null,
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@ -177,103 +220,16 @@ pub fn RepositoryQuery(comptime Model: type, comptime TableShape: type, comptime
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}
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}
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/// Set relations to eager load.
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pub fn with(self: *Self, relation: relations.ModelRelation) !void {
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// Take an array of eager relations (which can have subrelations).
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const allocator = self.arena.allocator();
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// Make a relation instance.
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const relationInstance = try allocator.create(relation.relation);
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// Add the new relation to a newly allocated array, with one more space.
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const newPos = if (self.queryConfig.with) |_with| _with.len else 0;
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var newWith = try allocator.alloc(relations.Eager, newPos + 1);
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newWith[newPos] = .{
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.field = relation.field,
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.relation = relationInstance.*.relation(),
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.with = &[0]relations.Eager{}, //TODO handle subrelations with dotted syntax
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};
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if (self.queryConfig.with) |_with| {
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// Copy existing relations.
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@memcpy(newWith[0..newPos], _with);
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// Free previous array.
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allocator.free(_with);
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}
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// Save the newly allocated array.
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self.queryConfig.with = newWith;
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}
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/// Build inline relations query part.
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fn buildInlineRelations(self: *Self) !?struct{
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select: []const u8,
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join: _sql.RawQuery,
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} {
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if (self.queryConfig.with) |_with| {
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// Initialize an ArrayList of query parts for relations.
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var inlineRelations = try std.ArrayList(_sql.RawQuery).initCapacity(self.arena.allocator(), _with.len);
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defer inlineRelations.deinit();
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var inlineRelationsSelect = try std.ArrayList([]const u8).initCapacity(self.arena.allocator(), _with.len);
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defer inlineRelationsSelect.deinit();
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// Initialize an ArrayList to store all loaded inline relations.
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var loadedRelations = std.ArrayList(relations.Eager).init(self.arena.allocator());
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defer loadedRelations.deinit();
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for (_with) |_relation| {
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// Append each inline relation to the ArrayList.
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if (_relation.relation.inlineMapping()) {
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try loadedRelations.append(_relation); // Store the loaded inline relation.
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// Get an allocator for local allocations.
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const localAllocator = self.arena.allocator();
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// Build table alias and fields prefix.
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const tableAlias = try std.fmt.allocPrint(localAllocator, "relations.{s}", .{_relation.field});
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defer localAllocator.free(tableAlias);
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const prefix = try std.fmt.allocPrint(localAllocator, "{s}.", .{tableAlias});
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defer localAllocator.free(prefix);
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// Alter query to get relation fields.
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try inlineRelations.append(try _relation.relation.genJoin(self.arena.allocator(), tableAlias));
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const relationSelect = try _relation.relation.genSelect(localAllocator, tableAlias, prefix);
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try inlineRelationsSelect.append(relationSelect);
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}
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}
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self.inlineRelations = try loadedRelations.toOwnedSlice();
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// Return the inline relations query part.
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return .{
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.select = try std.mem.join(self.arena.allocator(), ", ", inlineRelationsSelect.items),
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.join = try _sql.RawQuery.fromConcat(self.arena.allocator(), inlineRelations.items),
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};
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} else {
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// Nothing.
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return null;
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}
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}
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/// Build SQL query.
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pub fn buildSql(self: *Self) !void {
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// Build inline relations query part.
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const inlineRelations = try self.buildInlineRelations();
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defer if (inlineRelations) |_inlineRelations| self.arena.allocator().free(_inlineRelations.join.sql);
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defer if (inlineRelations) |_inlineRelations| self.arena.allocator().free(_inlineRelations.join.params);
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defer if (inlineRelations) |_inlineRelations| self.arena.allocator().free(_inlineRelations.select);
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// Build the full SQL query from all its parts.
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const sqlQuery = _sql.RawQuery{
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.sql = try std.mem.join(self.arena.allocator(), "", &[_][]const u8{
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"SELECT ", if (self.queryConfig.select) |_select| _select.sql else defaultSelectSql,
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if (inlineRelations) |_| ", " else "",
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if (inlineRelations) |_inlineRelations| _inlineRelations.select else "",
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fromClause,
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defaultJoin,
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if (self.queryConfig.join) |_| " " else "",
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if (self.queryConfig.join) |_join| _join.sql else "",
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if (inlineRelations) |_| " " else "",
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if (inlineRelations) |_inlineRelations| _inlineRelations.join.sql else "",
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if (self.queryConfig.where) |_| " WHERE " else "",
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if (self.queryConfig.where) |_where| _where.sql else "",
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";",
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@ -281,7 +237,6 @@ pub fn RepositoryQuery(comptime Model: type, comptime TableShape: type, comptime
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.params = try std.mem.concat(self.arena.allocator(), _sql.RawQueryParameter, &[_][]const _sql.RawQueryParameter{
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if (self.queryConfig.select) |_select| _select.params else &[0]_sql.RawQueryParameter{},
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if (self.queryConfig.join) |_join| _join.params else &[0]_sql.RawQueryParameter{},
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if (inlineRelations) |_inlineRelations| _inlineRelations.join.params else &[0]_sql.RawQueryParameter{},
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if (self.queryConfig.where) |_where| _where.params else &[0]_sql.RawQueryParameter{},
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})
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};
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@ -62,8 +62,7 @@ pub fn typedMany(
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};
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const FromKeyType = std.meta.fields(FromModel)[std.meta.fieldIndex(FromModel, fromRepositoryConfig.key[0]).?].type;
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const QueryType = _query.RepositoryQuery(ToModel, ToTable, toRepositoryConfig);
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const SelectBuilder = _sql.SelectBuilder(ToTable);
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const QueryType = _query.RepositoryQuery(ToModel, ToTable, toRepositoryConfig, null);
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return struct {
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const Self = @This();
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@ -72,12 +71,12 @@ pub fn typedMany(
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return false;
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}
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fn genJoin(_: *anyopaque, _: std.mem.Allocator, _: []const u8) !_sql.RawQuery {
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fn genJoin(_: *anyopaque, comptime _: []const u8) []const u8 {
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unreachable; // No possible join in a many relation.
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}
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fn genSelect(_: *anyopaque, allocator: std.mem.Allocator, table: []const u8, prefix: []const u8) ![]const u8 {
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return SelectBuilder.build(allocator, table, prefix);
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fn genSelect(_: *anyopaque, comptime table: []const u8, comptime prefix: []const u8) []const u8 {
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return _sql.SelectBuild(ToTable, table, prefix);
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}
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fn buildQuery(_: *anyopaque, opaqueModels: []const anyopaque, opaqueQuery: *anyopaque) !void {
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@ -181,8 +180,7 @@ fn typedOne(
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comptime config: OneConfiguration) type {
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const FromKeyType = std.meta.fields(FromModel)[std.meta.fieldIndex(FromModel, fromRepositoryConfig.key[0]).?].type;
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const QueryType = _query.RepositoryQuery(ToModel, ToTable, toRepositoryConfig);
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const SelectBuilder = _sql.SelectBuilder(ToTable);
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const QueryType = _query.RepositoryQuery(ToModel, ToTable, toRepositoryConfig, null);
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// Get foreign key from relation config or repository config.
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const foreignKey = switch (config) {
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@ -205,32 +203,29 @@ fn typedOne(
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return true;
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}
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fn genJoin(_: *anyopaque, allocator: std.mem.Allocator, alias: []const u8) !_sql.RawQuery {
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fn genJoin(_: *anyopaque, comptime alias: []const u8) []const u8 {
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return switch (config) {
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.direct => (.{
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.sql = try std.fmt.allocPrint(allocator, "LEFT JOIN \"" ++ toRepositoryConfig.table ++ "\" AS \"{s}\" ON " ++
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"\"" ++ fromRepositoryConfig.table ++ "\"." ++ foreignKey ++ " = \"{s}\"." ++ modelKey, .{alias, alias}),
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.params = &[0]_sql.RawQueryParameter{},
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}),
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.direct => (
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"LEFT JOIN \"" ++ toRepositoryConfig.table ++ "\" AS \"" ++ alias ++ "\" ON " ++
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"\"" ++ fromRepositoryConfig.table ++ "\"." ++ foreignKey ++ " = \"" ++ alias ++ "\"." ++ modelKey
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),
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.reverse => (.{
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.sql = try std.fmt.allocPrint(allocator, "LEFT JOIN \"" ++ toRepositoryConfig.table ++ "\" AS \"{s}\" ON " ++
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"\"" ++ fromRepositoryConfig.table ++ "\"." ++ modelKey ++ " = \"{s}\"." ++ foreignKey, .{alias, alias}),
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.params = &[0]_sql.RawQueryParameter{},
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}),
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.reverse => (
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"LEFT JOIN \"" ++ toRepositoryConfig.table ++ "\" AS \"" ++ alias ++ "\" ON " ++
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"\"" ++ fromRepositoryConfig.table ++ "\"." ++ modelKey ++ " = \"" ++ alias ++ "\"." ++ foreignKey
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),
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.through => |through| (.{
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.sql = try std.fmt.allocPrint(allocator, "LEFT JOIN \"" ++ through.table ++ "\" AS \"{s}_pivot\" ON " ++
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"\"" ++ fromRepositoryConfig.table ++ "\"." ++ foreignKey ++ " = " ++ "\"{s}_pivot\"." ++ through.joinForeignKey ++
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"LEFT JOIN \"" ++ toRepositoryConfig.table ++ "\" AS \"{s}\" ON " ++
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"\"{s}_pivot\"." ++ through.joinModelKey ++ " = " ++ "\"{s}\"." ++ modelKey, .{alias, alias, alias, alias, alias}),
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.params = &[0]_sql.RawQueryParameter{},
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}),
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.through => |through| (
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"LEFT JOIN \"" ++ through.table ++ "\" AS \"" ++ alias ++ "_pivot\" ON " ++
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"\"" ++ fromRepositoryConfig.table ++ "\"." ++ foreignKey ++ " = " ++ "\"" ++ alias ++ "_pivot\"." ++ through.joinForeignKey ++
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"LEFT JOIN \"" ++ toRepositoryConfig.table ++ "\" AS \"" ++ alias ++ "\" ON " ++
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"\"" ++ alias ++ "_pivot\"." ++ through.joinModelKey ++ " = " ++ "\"" ++ alias ++ "\"." ++ modelKey
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),
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};
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}
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fn genSelect(_: *anyopaque, allocator: std.mem.Allocator, table: []const u8, prefix: []const u8) ![]const u8 {
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return SelectBuilder.build(allocator, table, prefix);
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fn genSelect(_: *anyopaque, comptime table: []const u8, comptime prefix: []const u8) []const u8 {
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return _sql.SelectBuild(ToTable, table, prefix);
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}
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fn buildQuery(_: *anyopaque, opaqueModels: []const anyopaque, opaqueQuery: *anyopaque) !void {
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@ -296,8 +291,8 @@ pub const Relation = struct {
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instance: *anyopaque,
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inlineMapping: *const fn (self: *anyopaque) bool,
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genJoin: *const fn (self: *anyopaque, allocator: std.mem.Allocator, alias: []const u8) anyerror!_sql.RawQuery,
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genSelect: *const fn (self: *anyopaque, allocator: std.mem.Allocator, table: []const u8, prefix: []const u8) anyerror![]const u8,
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genJoin: *const fn (self: *anyopaque, comptime alias: []const u8) []const u8,
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genSelect: *const fn (self: *anyopaque, comptime table: []const u8, comptime prefix: []const u8) []const u8,
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buildQuery: *const fn (self: *anyopaque, models: []const anyopaque, query: *anyopaque) anyerror!void,
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},
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@ -308,13 +303,13 @@ pub const Relation = struct {
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}
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/// In case of inline mapping, generate a JOIN clause to retrieve the associated data.
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pub fn genJoin(self: Self, allocator: std.mem.Allocator, alias: []const u8) !_sql.RawQuery {
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return self._interface.genJoin(self._interface.instance, allocator, alias);
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pub fn genJoin(self: Self, comptime alias: []const u8) []const u8 {
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return self._interface.genJoin(self._interface.instance, alias);
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}
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/// Generate a SELECT clause to retrieve the associated data, with the given table and prefix.
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pub fn genSelect(self: Self, allocator: std.mem.Allocator, table: []const u8, prefix: []const u8) ![]const u8 {
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return self._interface.genSelect(self._interface.instance, allocator, table, prefix);
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pub fn genSelect(self: Self, comptime table: []const u8, comptime prefix: []const u8) []const u8 {
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return self._interface.genSelect(self._interface.instance, table, prefix);
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}
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/// Build the query to retrieve relation data.
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@ -110,7 +110,7 @@ pub fn Repository(comptime Model: type, comptime TableShape: type, comptime repo
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pub const TableType = TableShape;
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pub const config = repositoryConfig;
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pub const Query: type = query.RepositoryQuery(Model, TableShape, config);
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pub const Query: type = query.RepositoryQuery(Model, TableShape, config, null);
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pub const Insert: type = insert.RepositoryInsert(Model, TableShape, config, config.insertShape);
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/// Type of one model key.
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@ -152,6 +152,10 @@ pub fn Repository(comptime Model: type, comptime TableShape: type, comptime repo
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}
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};
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pub fn QueryWith(comptime with: []const _relations.ModelRelation) type {
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return query.RepositoryQuery(Model, TableShape, config, with);
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}
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pub fn InsertCustom(comptime InsertShape: type) type {
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return insert.RepositoryInsert(Model, TableShape, config, InsertShape);
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}
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23
src/sql.zig
23
src/sql.zig
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@ -213,6 +213,29 @@ pub fn SelectBuilder(comptime TableShape: type) type {
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};
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}
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/// Build a SELECT query part for a given table, renaming columns with the given prefix, at comptime.
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pub fn SelectBuild(comptime TableShape: type, comptime table: []const u8, comptime prefix: []const u8) []const u8 {
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// Initialize the selected columns string.
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var columnsSelect: []const u8 = "";
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var first = true;
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// For each field, generate a format string.
|
||||
for (@typeInfo(TableShape).Struct.fields) |field| {
|
||||
// Add ", " between all selected columns (just not the first one).
|
||||
if (first) {
|
||||
first = false;
|
||||
} else {
|
||||
columnsSelect = @ptrCast(columnsSelect ++ ", ");
|
||||
}
|
||||
|
||||
// Select the current field column.
|
||||
columnsSelect = @ptrCast(columnsSelect ++ "\"" ++ table ++ "\".\"" ++ field.name ++ "\" AS \"" ++ prefix ++ field.name ++ "\"");
|
||||
}
|
||||
|
||||
// Return built columns selection.
|
||||
return columnsSelect;
|
||||
}
|
||||
|
||||
|
||||
|
||||
|
||||
|
|
|
|||
|
|
@ -32,10 +32,11 @@ test "belongsTo" {
|
|||
};
|
||||
|
||||
// Build a query of submodels.
|
||||
var myQuery = repository.MySubmodelRepository.Query.init(std.testing.allocator, poolConnector.connector(), .{});
|
||||
var myQuery = repository.MySubmodelRepository.QueryWith(
|
||||
// Retrieve parents of submodels from relation.
|
||||
&[_]zrm.relations.ModelRelation{repository.MySubmodelRelations.parent}
|
||||
).init(std.testing.allocator, poolConnector.connector(), .{});
|
||||
defer myQuery.deinit();
|
||||
// Retrieve parents of submodels from relation.
|
||||
try myQuery.with(repository.MySubmodelRelations.parent);
|
||||
|
||||
try myQuery.buildSql();
|
||||
|
||||
|
|
|
|||
Loading…
Add table
Reference in a new issue