Add single query preparation

Fixes #2905
sqlc-dev · darkfeline · Jan 15, 2024 · Jan 18, 2024 · 7526980c24018ed7b927fdfb9d0d1c2962e796b1
commit 7526980c24018ed7b927fdfb9d0d1c2962e796b1
diff --git a/examples/ondeck/mysql/db.go b/examples/ondeck/mysql/db.go
diff --git a/examples/ondeck/postgresql/db.go b/examples/ondeck/postgresql/db.go
diff --git a/examples/ondeck/sqlite/db.go b/examples/ondeck/sqlite/db.go
diff --git a/internal/codegen/golang/templates/stdlib/dbCode.tmpl b/internal/codegen/golang/templates/stdlib/dbCode.tmpl
@@ -88,6 +88,18 @@ type Queries struct {
 	{{- end}}
 	{{- end}}
 }
+{{if .EmitPreparedQueries -}}
+{{range .GoQueries}}
+
+func (q *Queries) Prepare{{.MethodName}}(ctx context.Context) error {
+        var err error
+	if q.{{.FieldName}}, err = q.db.PrepareContext(ctx, {{.ConstantName}}); err != nil {
+		return fmt.Errorf("error preparing query {{.MethodName}}: %w", err)
+	}
+        return nil
+}
+{{- end}}
+{{- end}}
 
 {{if not .EmitMethodsWithDBArgument}}
 func (q *Queries) WithTx(tx *sql.Tx) *Queries {

diff --git a/internal/endtoend/testdata/prepared_queries/mysql/go/db.go b/internal/endtoend/testdata/prepared_queries/mysql/go/db.go
diff --git a/internal/endtoend/testdata/prepared_queries/postgresql/stdlib/go/db.go b/internal/endtoend/testdata/prepared_queries/postgresql/stdlib/go/db.go
diff --git a/internal/endtoend/testdata/sqlc_slice_prepared/sqlite/go/db.go b/internal/endtoend/testdata/sqlc_slice_prepared/sqlite/go/db.go