move pgruntime internal helpers to internal/gq

I want to use these in package pgtest.

4 files changed, 79 insertions, 71 deletions

diff --git a/internal/gq/gq.go b/internal/gq/gq.go
new file mode 100644
index 0000000..0eb2b0c
--- /dev/null
+++ b/internal/gq/gq.go
@@ -0,0 +1,66 @@
+// SPDX-FileCopyrightText: 2026 Stefan Majewsky <majewsky@gmx.net>
+// SPDX-License-Identifier: Apache-2.0
+
+// Package gq contains helpers for gsql ("gsql query" -> gq).
+// TODO: most of these functions should be either in gsql as public API, or in Oblast
+package gq
+
+import (
+	"context"
+	"database/sql"
+
+	"go.xyrillian.de/gg/errext"
+	"go.xyrillian.de/gg/gsql"
+)
+
+// ExecQuery is a convenience function for executing a one-off SQL query returning no rows.
+func ExecQuery(ctx context.Context, db gsql.Handle, query string, args []any) (sql.Result, error) {
+	stmt, err := db.GSQLPrepare(ctx, query, false)
+	if err != nil {
+		return nil, err
+	}
+	result, err := stmt.Exec(ctx, args)
+	return result, errext.WithCleanup(err, "stmt.Close", stmt.Close())
+}
+
+// QueryRow is a convenience function for executing a one-off SQL query returning one row.
+func QueryRow(ctx context.Context, db gsql.Handle, query string, args, slots []any) error {
+	stmt, err := db.GSQLPrepare(ctx, query, false)
+	if err != nil {
+		return err
+	}
+	err = stmt.QueryRow(ctx, args, slots)
+	return errext.WithCleanup(err, "stmt.Close", stmt.Close())
+}
+
+// SelectOneValue is a convenience function for executing a one-off SQL query returning one value.
+func SelectOneValue[T any](ctx context.Context, db gsql.Handle, query string, args ...any) (T, error) {
+	stmt, err := db.GSQLPrepare(ctx, query, false)
+	if err != nil {
+		var none T
+		return none, err
+	}
+
+	var result T
+	err = stmt.QueryRow(ctx, args, []any{&result})
+	return result, errext.WithCleanup(err, "stmt.Close", stmt.Close())
+}
+
+// SelectSeveralValues is a convenience function for executing a one-off SQL query returning several single-column rows.
+func SelectSeveralValues[T any](ctx context.Context, db gsql.Handle, query string, args ...any) ([]T, error) {
+	rows, err := db.GSQLQuery(ctx, query, args)
+	if err != nil {
+		return nil, err
+	}
+	var result []T
+	for rows.Next() {
+		// TODO: this should share growRecordSlice() from Oblast to optimize allocations
+		var value T
+		err := rows.Scan(&value)
+		if err != nil {
+			return nil, errext.WithCleanup(err, "rows.Close", rows.Close())
+		}
+		result = append(result, value)
+	}
+	return result, errext.WithCleanup(nil, "rows.Err", rows.Err())
+}
diff --git a/pgruntime/behavior.go b/pgruntime/behavior.go
index 03ff338..debdef4 100644
--- a/pgruntime/behavior.go
+++ b/pgruntime/behavior.go
@@ -9,6 +9,7 @@ import (
 	"slices"
 
 	"go.xyrillian.de/gg/gsql"
+	"go.xyrillian.de/gg/internal/gq"
 )
 
 // ConnectionBehavior contains configuration for [Connector.Connect] and [Connector.ConnectForTest].
@@ -62,13 +63,13 @@ func (b ConnectionBehavior) applyTo(ctx context.Context, db gsql.ConnectionHandl
 
 func applyMigrations(ctx context.Context, db gsql.ConnectionHandle, migrations map[int64]string) error {
 	// apply schema_migrations table schema
-	_, err := execQuery(ctx, db, MigrationsSchema, nil)
+	_, err := gq.ExecQuery(ctx, db, MigrationsSchema, nil)
 	if err != nil {
 		return fmt.Errorf("could not apply schema_migrations table schema: %w", err)
 	}
 
 	// read schema_migrations table
-	rowCount, err := selectOneValue[int64](ctx, db, `SELECT COUNT(*) FROM schema_migrations`)
+	rowCount, err := gq.SelectOneValue[int64](ctx, db, `SELECT COUNT(*) FROM schema_migrations`)
 	if err != nil {
 		return fmt.Errorf("could not check row count for schema_migrations: %w", err)
 	}
@@ -79,12 +80,12 @@ func applyMigrations(ctx context.Context, db gsql.ConnectionHandle, migrations m
 	switch rowCount {
 	case 0:
 		currentVersion = 0
-		_, err = execQuery(ctx, db, `INSERT INTO schema_migrations (version, dirty) VALUES (0, FALSE)`, nil)
+		_, err = gq.ExecQuery(ctx, db, `INSERT INTO schema_migrations (version, dirty) VALUES (0, FALSE)`, nil)
 		if err != nil {
 			return fmt.Errorf("could not initialize schema_migrations record: %w", err)
 		}
 	case 1:
-		err = queryRow(ctx, db, `SELECT version, dirty FROM schema_migrations`, nil, []any{&currentVersion, &dirty})
+		err = gq.QueryRow(ctx, db, `SELECT version, dirty FROM schema_migrations`, nil, []any{&currentVersion, &dirty})
 		if err != nil {
 			return fmt.Errorf("could not read schema_migrations record: %w", err)
 		}
@@ -112,7 +113,7 @@ func applyMigrations(ctx context.Context, db gsql.ConnectionHandle, migrations m
 		err := db.GSQLTransact(ctx, func(tx gsql.Handle) error {
 			// ensure that nobody else is migrating until we are done
 			var actualVersion int64
-			err := queryRow(ctx, db, `SELECT version FROM schema_migrations FOR UPDATE`, nil, []any{&actualVersion})
+			err := gq.QueryRow(ctx, db, `SELECT version FROM schema_migrations FOR UPDATE`, nil, []any{&actualVersion})
 			if err != nil {
 				return fmt.Errorf("could not obtain lock for schema migration: %w", err)
 			}
@@ -125,11 +126,11 @@ func applyMigrations(ctx context.Context, db gsql.ConnectionHandle, migrations m
 			}
 
 			// perform the next migration
-			_, err = execQuery(ctx, db, migrations[version], nil)
+			_, err = gq.ExecQuery(ctx, db, migrations[version], nil)
 			if err != nil {
 				return fmt.Errorf("could not execute schema migration: %w", err)
 			}
-			_, err = execQuery(ctx, db, `UPDATE schema_migrations SET version = $1, dirty = FALSE`, []any{version})
+			_, err = gq.ExecQuery(ctx, db, `UPDATE schema_migrations SET version = $1, dirty = FALSE`, []any{version})
 			if err != nil {
 				return fmt.Errorf("could not update schema_migrations record: %w", err)
 			}
diff --git a/pgruntime/connector.go b/pgruntime/connector.go
index 5276a26..76a45f1 100644
--- a/pgruntime/connector.go
+++ b/pgruntime/connector.go
@@ -15,6 +15,7 @@ import (
 	"go.xyrillian.de/gg/assert"
 	"go.xyrillian.de/gg/errext"
 	"go.xyrillian.de/gg/gsql"
+	"go.xyrillian.de/gg/internal/gq"
 )
 
 // Connector describes how to connect to a PostgreSQL database given a [libpq-style connection URI].
@@ -135,14 +136,14 @@ func (c Connector[T]) ConnectForTest(t assert.TestingTB, behavior ConnectionBeha
 
 func createDatabaseIfMissing(ctx context.Context, db gsql.Handle, dbName string) error {
 	// check if database exists
-	exists, err := selectOneValue[bool](ctx, db, `SELECT COUNT(*) > 0 FROM pg_catalog.pg_database WHERE datname = $1`, dbName)
+	exists, err := gq.SelectOneValue[bool](ctx, db, `SELECT COUNT(*) > 0 FROM pg_catalog.pg_database WHERE datname = $1`, dbName)
 	if err != nil {
 		return fmt.Errorf("while reading from pg_catalog.pg_database: %w", err)
 	}
 
 	// create database if necessary
 	if !exists {
-		_, err = execQuery(ctx, db, "CREATE DATABASE "+quoteIdentifier(dbName), nil)
+		_, err = gq.ExecQuery(ctx, db, "CREATE DATABASE "+quoteIdentifier(dbName), nil)
 		if err != nil {
 			return fmt.Errorf("during CREATE DATABASE: %w", err)
 		}
@@ -158,7 +159,7 @@ func resetTestDatabase(ctx context.Context, db gsql.Handle, params testSetupPara
 		condition += ` AND table_name != 'schema_migrations'`
 	}
 	query := fmt.Sprintf(`SELECT quote_ident(table_name) FROM information_schema.tables WHERE %s ORDER BY table_name`, condition)
-	quotedTableNames, err := selectSeveralValues[string](ctx, db, query)
+	quotedTableNames, err := gq.SelectSeveralValues[string](ctx, db, query)
 	if err != nil {
 		return fmt.Errorf("while listing tables to truncate: %w", err)
 	}
@@ -166,7 +167,7 @@ func resetTestDatabase(ctx context.Context, db gsql.Handle, params testSetupPara
 	// truncate all tables at once
 	if len(quotedTableNames) > 0 {
 		query = fmt.Sprintf(`TRUNCATE %s RESTART IDENTITY CASCADE`, strings.Join(quotedTableNames, ", "))
-		_, err = execQuery(ctx, db, query, nil)
+		_, err = gq.ExecQuery(ctx, db, query, nil)
 		if err != nil {
 			return fmt.Errorf("during %s: %w", query, err)
 		}
diff --git a/pgruntime/helpers.go b/pgruntime/helpers.go
index 1019e6e..d68b920 100644
--- a/pgruntime/helpers.go
+++ b/pgruntime/helpers.go
@@ -4,69 +4,9 @@
 package pgruntime
 
 import (
-	"context"
-	"database/sql"
 	"strings"
-
-	"go.xyrillian.de/gg/errext"
-	"go.xyrillian.de/gg/gsql"
 )
 
-// Convenience function for executing a one-off SQL query returning no rows.
-// TODO: move to gsql
-func execQuery(ctx context.Context, db gsql.Handle, query string, args []any) (sql.Result, error) {
-	stmt, err := db.GSQLPrepare(ctx, query, false)
-	if err != nil {
-		return nil, err
-	}
-	result, err := stmt.Exec(ctx, args)
-	return result, errext.WithCleanup(err, "stmt.Close", stmt.Close())
-}
-
-// Convenience function for executing a one-off SQL query returning one row.
-func queryRow(ctx context.Context, db gsql.Handle, query string, args, slots []any) error {
-	stmt, err := db.GSQLPrepare(ctx, query, false)
-	if err != nil {
-		return err
-	}
-	err = stmt.QueryRow(ctx, args, slots)
-	return errext.WithCleanup(err, "stmt.Close", stmt.Close())
-}
-
-// Convenience function for executing a one-off SQL query returning one value.
-// TODO: move to gsql
-func selectOneValue[T any](ctx context.Context, db gsql.Handle, query string, args ...any) (T, error) {
-	stmt, err := db.GSQLPrepare(ctx, query, false)
-	if err != nil {
-		var none T
-		return none, err
-	}
-
-	var result T
-	err = stmt.QueryRow(ctx, args, []any{&result})
-	return result, errext.WithCleanup(err, "stmt.Close", stmt.Close())
-}
-
-// Convenience function for executing a one-off SQL query returning several single-column rows.
-// TODO: move to gsql (and also add ForeachValue with a callback instead of a slice return, maybe even ForeachPair and ForeachTriple)
-func selectSeveralValues[T any](ctx context.Context, db gsql.Handle, query string, args ...any) ([]T, error) {
-	rows, err := db.GSQLQuery(ctx, query, args)
-	if err != nil {
-		return nil, err
-	}
-	var result []T
-	for rows.Next() {
-		// TODO: this should share growRecordSlice() from Oblast to optimize allocations
-		var value T
-		err := rows.Scan(&value)
-		if err != nil {
-			return nil, errext.WithCleanup(err, "rows.Close", rows.Close())
-		}
-		result = append(result, value)
-	}
-	return result, errext.WithCleanup(nil, "rows.Err", rows.Err())
-}
-
 // Convenience function for preparing an identifier that needs to be inserted into a query verbatim
 // (e.g. a database name for CREATE DATABASE).
 func quoteIdentifier(name string) string {