From 5d309bcf5bbb4b7cb2fd3c582803b137192a259d Mon Sep 17 00:00:00 2001
From: adlerhurst <27845747+adlerhurst@users.noreply.github.com>
Date: Fri, 25 Jul 2025 16:16:45 +0200
Subject: [PATCH] feat(database): implement sql adapter for backwards
 compatibility

---
 .../v3/storage/database/dialect/sql/conn.go   |  59 ++++++++++
 .../v3/storage/database/dialect/sql/doc.go    |   3 +
 .../v3/storage/database/dialect/sql/error.go  |  41 +++++++
 .../v3/storage/database/dialect/sql/pool.go   |  74 +++++++++++++
 .../v3/storage/database/dialect/sql/rows.go   |  79 ++++++++++++++
 .../storage/database/dialect/sql/savepoint.go |  69 ++++++++++++
 backend/v3/storage/database/dialect/sql/tx.go | 103 ++++++++++++++++++
 7 files changed, 428 insertions(+)
 create mode 100644 backend/v3/storage/database/dialect/sql/conn.go
 create mode 100644 backend/v3/storage/database/dialect/sql/doc.go
 create mode 100644 backend/v3/storage/database/dialect/sql/error.go
 create mode 100644 backend/v3/storage/database/dialect/sql/pool.go
 create mode 100644 backend/v3/storage/database/dialect/sql/rows.go
 create mode 100644 backend/v3/storage/database/dialect/sql/savepoint.go
 create mode 100644 backend/v3/storage/database/dialect/sql/tx.go

diff --git a/backend/v3/storage/database/dialect/sql/conn.go b/backend/v3/storage/database/dialect/sql/conn.go
new file mode 100644
index 0000000000..967ed2d1e8
--- /dev/null
+++ b/backend/v3/storage/database/dialect/sql/conn.go
@@ -0,0 +1,59 @@
+package sql
+
+import (
+	"context"
+	"database/sql"
+
+	"github.com/zitadel/zitadel/backend/v3/storage/database"
+)
+
+type sqlConn struct {
+	*sql.Conn
+}
+
+var _ database.Client = (*sqlConn)(nil)
+
+// Release implements [database.Client].
+func (c *sqlConn) Release(_ context.Context) error {
+	return c.Close()
+}
+
+// Begin implements [database.Client].
+func (c *sqlConn) Begin(ctx context.Context, opts *database.TransactionOptions) (database.Transaction, error) {
+	tx, err := c.BeginTx(ctx, transactionOptionsToSQL(opts))
+	if err != nil {
+		return nil, wrapError(err)
+	}
+	return &sqlTx{tx}, nil
+}
+
+// Query implements sql.Client.
+// Subtle: this method shadows the method (*Conn).Query of pgxConn.Conn.
+func (c *sqlConn) Query(ctx context.Context, sql string, args ...any) (database.Rows, error) {
+	rows, err := c.QueryContext(ctx, sql, args...)
+	if err != nil {
+		return nil, wrapError(err)
+	}
+	return &Rows{rows}, nil
+}
+
+// QueryRow implements sql.Client.
+// Subtle: this method shadows the method (*Conn).QueryRow of pgxConn.Conn.
+func (c *sqlConn) QueryRow(ctx context.Context, sql string, args ...any) database.Row {
+	return &Row{c.QueryRowContext(ctx, sql, args...)}
+}
+
+// Exec implements [database.Pool].
+// Subtle: this method shadows the method (Pool).Exec of pgxPool.Pool.
+func (c *sqlConn) Exec(ctx context.Context, sql string, args ...any) (int64, error) {
+	res, err := c.ExecContext(ctx, sql, args...)
+	if err != nil {
+		return 0, wrapError(err)
+	}
+	return res.RowsAffected()
+}
+
+// Migrate implements [database.Migrator].
+func (c *sqlConn) Migrate(ctx context.Context) error {
+	return ErrMigrate
+}
diff --git a/backend/v3/storage/database/dialect/sql/doc.go b/backend/v3/storage/database/dialect/sql/doc.go
new file mode 100644
index 0000000000..a6b2782dc5
--- /dev/null
+++ b/backend/v3/storage/database/dialect/sql/doc.go
@@ -0,0 +1,3 @@
+// [database/sql] implementation of the interfaces defined in the database package.
+// This package is used to migrate from event driven to relational Zitadel.
+package sql
diff --git a/backend/v3/storage/database/dialect/sql/error.go b/backend/v3/storage/database/dialect/sql/error.go
new file mode 100644
index 0000000000..f01b1e70e1
--- /dev/null
+++ b/backend/v3/storage/database/dialect/sql/error.go
@@ -0,0 +1,41 @@
+package sql
+
+import (
+	"database/sql"
+	"errors"
+
+	"github.com/jackc/pgx/v5"
+	"github.com/jackc/pgx/v5/pgconn"
+
+	"github.com/zitadel/zitadel/backend/v3/storage/database"
+)
+
+var ErrMigrate = errors.New("sql does not support migrations, use a different dialect")
+
+func wrapError(err error) error {
+	if err == nil {
+		return nil
+	}
+	if errors.Is(err, pgx.ErrNoRows) || errors.Is(err, sql.ErrNoRows) {
+		return database.NewNoRowFoundError(err)
+	}
+	var pgxErr *pgconn.PgError
+	if !errors.As(err, &pgxErr) {
+		return database.NewUnknownError(err)
+	}
+	switch pgxErr.Code {
+	// 23514: check_violation - A value violates a CHECK constraint.
+	case "23514":
+		return database.NewCheckError(pgxErr.TableName, pgxErr.ConstraintName, pgxErr)
+	// 23505: unique_violation - A value violates a UNIQUE constraint.
+	case "23505":
+		return database.NewUniqueError(pgxErr.TableName, pgxErr.ConstraintName, pgxErr)
+	// 23503: foreign_key_violation - A value violates a foreign key constraint.
+	case "23503":
+		return database.NewForeignKeyError(pgxErr.TableName, pgxErr.ConstraintName, pgxErr)
+	// 23502: not_null_violation - A value violates a NOT NULL constraint.
+	case "23502":
+		return database.NewNotNullError(pgxErr.TableName, pgxErr.ConstraintName, pgxErr)
+	}
+	return database.NewUnknownError(err)
+}
diff --git a/backend/v3/storage/database/dialect/sql/pool.go b/backend/v3/storage/database/dialect/sql/pool.go
new file mode 100644
index 0000000000..0c4a0cac66
--- /dev/null
+++ b/backend/v3/storage/database/dialect/sql/pool.go
@@ -0,0 +1,74 @@
+package sql
+
+import (
+	"context"
+	"database/sql"
+
+	"github.com/zitadel/zitadel/backend/v3/storage/database"
+)
+
+type sqlPool struct {
+	*sql.DB
+}
+
+var _ database.Pool = (*sqlPool)(nil)
+
+func SQLPool(db *sql.DB) *sqlPool {
+	return &sqlPool{
+		DB: db,
+	}
+}
+
+// Acquire implements [database.Pool].
+func (c *sqlPool) Acquire(ctx context.Context) (database.Client, error) {
+	conn, err := c.Conn(ctx)
+	if err != nil {
+		return nil, wrapError(err)
+	}
+	return &sqlConn{Conn: conn}, nil
+}
+
+// Query implements [database.Pool].
+// Subtle: this method shadows the method (Pool).Query of pgxPool.Pool.
+func (c *sqlPool) Query(ctx context.Context, sql string, args ...any) (database.Rows, error) {
+	rows, err := c.QueryContext(ctx, sql, args...)
+	if err != nil {
+		return nil, wrapError(err)
+	}
+	return &Rows{rows}, nil
+}
+
+// QueryRow implements [database.Pool].
+// Subtle: this method shadows the method (Pool).QueryRow of pgxPool.Pool.
+func (c *sqlPool) QueryRow(ctx context.Context, sql string, args ...any) database.Row {
+	return &Row{c.QueryRowContext(ctx, sql, args...)}
+}
+
+// Exec implements [database.Pool].
+// Subtle: this method shadows the method (Pool).Exec of pgxPool.Pool.
+func (c *sqlPool) Exec(ctx context.Context, sql string, args ...any) (int64, error) {
+	res, err := c.ExecContext(ctx, sql, args...)
+	if err != nil {
+		return 0, wrapError(err)
+	}
+	return res.RowsAffected()
+}
+
+// Begin implements [database.Pool].
+func (c *sqlPool) Begin(ctx context.Context, opts *database.TransactionOptions) (database.Transaction, error) {
+	tx, err := c.BeginTx(ctx, transactionOptionsToSQL(opts))
+	if err != nil {
+		return nil, wrapError(err)
+	}
+	return &sqlTx{tx}, nil
+}
+
+// Close implements [database.Pool].
+func (c *sqlPool) Close(_ context.Context) error {
+	return c.DB.Close()
+}
+
+// Migrate implements [database.Migrator].
+func (c *sqlPool) Migrate(ctx context.Context) error {
+	return ErrMigrate
+}
diff --git a/backend/v3/storage/database/dialect/sql/rows.go b/backend/v3/storage/database/dialect/sql/rows.go
new file mode 100644
index 0000000000..b2265ca1ca
--- /dev/null
+++ b/backend/v3/storage/database/dialect/sql/rows.go
@@ -0,0 +1,79 @@
+package sql
+
+import (
+	"database/sql"
+
+	pgxscan "github.com/georgysavva/scany/v2/dbscan"
+	"github.com/jackc/pgx/v5"
+
+	"github.com/zitadel/zitadel/backend/v3/storage/database"
+)
+
+var (
+	_ database.Rows            = (*Rows)(nil)
+	_ database.CollectableRows = (*Rows)(nil)
+	_ database.Row             = (*Row)(nil)
+)
+
+type Row struct{ pgx.Row }
+
+// Scan implements [database.Row].
+// Subtle: this method shadows the method ([pgx.Row]).Scan of Row.Row.
+func (r *Row) Scan(dest ...any) error {
+	return wrapError(r.Row.Scan(dest...))
+}
+
+type Rows struct{ *sql.Rows }
+
+// Err implements [database.Rows].
+// Subtle: this method shadows the method ([pgx.Rows]).Err of Rows.Rows.
+func (r *Rows) Err() error {
+	return wrapError(r.Rows.Err())
+}
+
+func (r *Rows) Scan(dest ...any) error {
+	return wrapError(r.Rows.Scan(dest...))
+}
+
+// Collect implements [database.CollectableRows].
+// See [this page](https://github.com/georgysavva/scany/blob/master/dbscan/doc.go#L8) for additional details.
+func (r *Rows) Collect(dest any) (err error) {
+	defer func() {
+		closeErr := r.Close()
+		if err == nil {
+			err = closeErr
+		}
+	}()
+	return wrapError(pgxscan.ScanAll(dest, r.Rows))
+}
+
+// CollectFirst implements [database.CollectableRows].
+// See [this page](https://github.com/georgysavva/scany/blob/master/dbscan/doc.go#L8) for additional details.
+func (r *Rows) CollectFirst(dest any) (err error) {
+	defer func() {
+		closeErr := r.Close()
+		if err == nil {
+			err = closeErr
+		}
+	}()
+	return wrapError(pgxscan.ScanRow(dest, r.Rows))
+}
+
+// CollectExactlyOneRow implements [database.CollectableRows].
+// See [this page](https://github.com/georgysavva/scany/blob/master/dbscan/doc.go#L8) for additional details.
+func (r *Rows) CollectExactlyOneRow(dest any) (err error) {
+	defer func() {
+		closeErr := r.Close()
+		if err == nil {
+			err = closeErr
+		}
+	}()
+	return wrapError(pgxscan.ScanOne(dest, r.Rows))
+}
+
+// Close implements [database.Rows].
+// Subtle: this method shadows the method (Rows).Close of Rows.Rows.
+func (r *Rows) Close() error {
+	r.Rows.Close()
+	return nil
+}
diff --git a/backend/v3/storage/database/dialect/sql/savepoint.go b/backend/v3/storage/database/dialect/sql/savepoint.go
new file mode 100644
index 0000000000..1933771e9a
--- /dev/null
+++ b/backend/v3/storage/database/dialect/sql/savepoint.go
@@ -0,0 +1,69 @@
+package sql
+
+import (
+	"context"
+	"errors"
+
+	"github.com/zitadel/zitadel/backend/v3/storage/database"
+)
+
+var _ database.Transaction = (*sqlSavepoint)(nil)
+
+const (
+	savepointName       = "zitadel_savepoint"
+	createSavepoint     = "SAVEPOINT " + savepointName
+	rollbackToSavepoint = "ROLLBACK TO SAVEPOINT " + savepointName
+	commitSavepoint     = "RELEASE SAVEPOINT " + savepointName
+)
+
+type sqlSavepoint struct {
+	parent database.Transaction
+}
+
+// Commit implements [database.Transaction].
+func (s *sqlSavepoint) Commit(ctx context.Context) error {
+	_, err := s.parent.Exec(ctx, commitSavepoint)
+	return wrapError(err)
+}
+
+// Rollback implements [database.Transaction].
+func (s *sqlSavepoint) Rollback(ctx context.Context) error {
+	_, err := s.parent.Exec(ctx, rollbackToSavepoint)
+	return wrapError(err)
+}
+
+// End implements [database.Transaction].
+func (s *sqlSavepoint) End(ctx context.Context, err error) error {
+	if err != nil {
+		rollbackErr := s.Rollback(ctx)
+		if rollbackErr != nil {
+			err = errors.Join(err, rollbackErr)
+		}
+		return err
+	}
+	return s.Commit(ctx)
+}
+
+// Query implements [database.Transaction].
+// Subtle: this method shadows the method (Tx).Query of pgxTx.Tx.
+func (s *sqlSavepoint) Query(ctx context.Context, sql string, args ...any) (database.Rows, error) {
+	return s.parent.Query(ctx, sql, args...)
+}
+
+// QueryRow implements [database.Transaction].
+// Subtle: this method shadows the method (Tx).QueryRow of pgxTx.Tx.
+func (s *sqlSavepoint) QueryRow(ctx context.Context, sql string, args ...any) database.Row {
+	return s.parent.QueryRow(ctx, sql, args...)
+}
+
+// Exec implements [database.Transaction].
+// Subtle: this method shadows the method (Pool).Exec of pgxPool.Pool.
+func (s *sqlSavepoint) Exec(ctx context.Context, sql string, args ...any) (int64, error) {
+	return s.parent.Exec(ctx, sql, args...)
+}
+
+// Begin implements [database.Transaction].
+// As postgres does not support nested transactions we use savepoints to emulate them.
+func (s *sqlSavepoint) Begin(ctx context.Context) (database.Transaction, error) {
+	return s.parent.Begin(ctx)
+}
diff --git a/backend/v3/storage/database/dialect/sql/tx.go b/backend/v3/storage/database/dialect/sql/tx.go
new file mode 100644
index 0000000000..c2da0e650b
--- /dev/null
+++ b/backend/v3/storage/database/dialect/sql/tx.go
@@ -0,0 +1,103 @@
+package sql
+
+import (
+	"context"
+	"database/sql"
+	"errors"
+
+	"github.com/zitadel/zitadel/backend/v3/storage/database"
+)
+
+type sqlTx struct{ *sql.Tx }
+
+var _ database.Transaction = (*sqlTx)(nil)
+
+func SQLTx(tx *sql.Tx) *sqlTx {
+	return &sqlTx{
+		Tx: tx,
+	}
+}
+
+// Commit implements [database.Transaction].
+func (tx *sqlTx) Commit(ctx context.Context) error {
+	return wrapError(tx.Tx.Commit())
+}
+
+// Rollback implements [database.Transaction].
+func (tx *sqlTx) Rollback(ctx context.Context) error {
+	return wrapError(tx.Tx.Rollback())
+}
+
+// End implements [database.Transaction].
+func (tx *sqlTx) End(ctx context.Context, err error) error {
+	if err != nil {
+		rollbackErr := tx.Rollback(ctx)
+		if rollbackErr != nil {
+			err = errors.Join(err, rollbackErr)
+		}
+		return err
+	}
+	return tx.Commit(ctx)
+}
+
+// Query implements [database.Transaction].
+// Subtle: this method shadows the method (Tx).Query of pgxTx.Tx.
+func (tx *sqlTx) Query(ctx context.Context, sql string, args ...any) (database.Rows, error) {
+	rows, err := tx.QueryContext(ctx, sql, args...)
+	if err != nil {
+		return nil, wrapError(err)
+	}
+	return &Rows{rows}, nil
+}
+
+// QueryRow implements [database.Transaction].
+// Subtle: this method shadows the method (Tx).QueryRow of pgxTx.Tx.
+func (tx *sqlTx) QueryRow(ctx context.Context, sql string, args ...any) database.Row {
+	return &Row{tx.QueryRowContext(ctx, sql, args...)}
+}
+
+// Exec implements [database.Transaction].
+// Subtle: this method shadows the method (Pool).Exec of pgxPool.Pool.
+func (tx *sqlTx) Exec(ctx context.Context, sql string, args ...any) (int64, error) {
+	res, err := tx.ExecContext(ctx, sql, args...)
+	if err != nil {
+		return 0, wrapError(err)
+	}
+	return res.RowsAffected()
+}
+
+// Begin implements [database.Transaction].
+// As postgres does not support nested transactions we use savepoints to emulate them.
+func (tx *sqlTx) Begin(ctx context.Context) (database.Transaction, error) {
+	_, err := tx.ExecContext(ctx, createSavepoint)
+	if err != nil {
+		return nil, wrapError(err)
+	}
+	return &sqlSavepoint{tx}, nil
+}
+
+func transactionOptionsToSQL(opts *database.TransactionOptions) *sql.TxOptions {
+	if opts == nil {
+		return nil
+	}
+
+	return &sql.TxOptions{
+		Isolation: isolationToSQL(opts.IsolationLevel),
+		ReadOnly:  accessModeToSQL(opts.AccessMode),
+	}
+}
+
+func isolationToSQL(isolation database.IsolationLevel) sql.IsolationLevel {
+	switch isolation {
+	case database.IsolationLevelSerializable:
+		return sql.LevelSerializable
+	case database.IsolationLevelReadCommitted:
+		return sql.LevelReadCommitted
+	default:
+		return sql.LevelSerializable
+	}
+}
+
+func accessModeToSQL(accessMode database.AccessMode) bool {
+	return accessMode == database.AccessModeReadOnly
+}