session: annotate the previous statement to the error when transaction commit failed

ddl/db_test.go

@@ -3232,7 +3232,7 @@ func (s *testDBSuite2) TestLockTables(c *C) {
 	tk2.MustExec("lock tables t1 write")
 	_, err = tk.Exec("commit")
 	c.Assert(err, NotNil)
-	c.Assert(err.Error(), Equals, "[domain:2]Information schema is changed. [try again later]")
+	c.Assert(err.Error(), Equals, "previous statement: insert into t1 set a=1: [domain:2]Information schema is changed. [try again later]")
 
 	// Test lock table by other session in transaction and commit with retry.
 	tk.MustExec("unlock tables")

executor/adapter.go

@@ -179,7 +179,8 @@ func (a *recordSet) NewChunk() *chunk.Chunk {
 func (a *recordSet) Close() error {
 	err := a.executor.Close()
 	a.stmt.LogSlowQuery(a.txnStartTS, a.lastErr == nil)
-	a.stmt.Ctx.GetSessionVars().PrevStmt = a.stmt.OriginText()
+	sessVars := a.stmt.Ctx.GetSessionVars()
+	sessVars.PrevStmt = FormatSQL(a.stmt.OriginText(), sessVars)
 	a.stmt.logAudit()
 	a.stmt.SummaryStmt()
 	return err
@@ -750,7 +751,7 @@ func (a *ExecStmt) LogSlowQuery(txnTS uint64, succ bool) {
 		Succ:        succ,
 	}
 	if _, ok := a.StmtNode.(*ast.CommitStmt); ok {
-		slowItems.PrevStmt = FormatSQL(sessVars.PrevStmt, sessVars)
+		slowItems.PrevStmt = sessVars.PrevStmt
 	}
 	if costTime < threshold {
 		logutil.SlowQueryLogger.Debug(sessVars.SlowLogFormat(slowItems))

session/session_test.go

@@ -1590,12 +1590,12 @@ func (s *testSessionSuite) TestUnique(c *C) {
 	c.Assert(err, NotNil)
 	// Check error type and error message
 	c.Assert(terror.ErrorEqual(err, kv.ErrKeyExists), IsTrue, Commentf("err %v", err))
-	c.Assert(err.Error(), Equals, "[kv:1062]Duplicate entry '1' for key 'PRIMARY'")
+	c.Assert(err.Error(), Equals, "previous statement: insert into test(id, val) values(1, 1);: [kv:1062]Duplicate entry '1' for key 'PRIMARY'")
 
 	_, err = tk1.Exec("commit")
 	c.Assert(err, NotNil)
 	c.Assert(terror.ErrorEqual(err, kv.ErrKeyExists), IsTrue, Commentf("err %v", err))
-	c.Assert(err.Error(), Equals, "[kv:1062]Duplicate entry '2' for key 'val'")
+	c.Assert(err.Error(), Equals, "previous statement: insert into test(id, val) values(2, 2);: [kv:1062]Duplicate entry '2' for key 'val'")
 
 	// Test for https://github.com/pingcap/tidb/issues/463
 	tk.MustExec("drop table test;")

session/tidb.go

@@ -160,7 +160,8 @@ func Compile(ctx context.Context, sctx sessionctx.Context, stmtNode ast.StmtNode
 	return stmt, err
 }
 
-func finishStmt(ctx context.Context, sctx sessionctx.Context, se *session, sessVars *variable.SessionVars, meetsErr error) error {
+func finishStmt(ctx context.Context, sctx sessionctx.Context, se *session, sessVars *variable.SessionVars,
+	meetsErr error, sql sqlexec.Statement) error {
 	if meetsErr != nil {
 		if !sessVars.InTxn() {
 			logutil.BgLogger().Info("rollbackTxn for ddl/autocommit failed")
@@ -173,7 +174,13 @@ func finishStmt(ctx context.Context, sctx sessionctx.Context, se *session, sessV
 	}
 
 	if !sessVars.InTxn() {
-		return se.CommitTxn(ctx)
+		if err := se.CommitTxn(ctx); err != nil {
+			if _, ok := sql.(*executor.ExecStmt).StmtNode.(*ast.CommitStmt); ok {
+				err = errors.Annotatef(err, "previous statement: %s", se.GetSessionVars().PrevStmt)
+			}
+			return err
+		}
+		return nil
 	}
 
 	return checkStmtLimit(ctx, sctx, se)
@@ -219,7 +226,7 @@ func runStmt(ctx context.Context, sctx sessionctx.Context, s sqlexec.Statement)
 		if rs == nil {
 			s.(*executor.ExecStmt).LogSlowQuery(origTxnCtx.StartTS, err == nil)
 			s.(*executor.ExecStmt).SummaryStmt()
-			sessVars.PrevStmt = s.OriginText()
+			sessVars.PrevStmt = executor.FormatSQL(s.OriginText(), sessVars)
 		}
 	}()
 
@@ -248,7 +255,7 @@ func runStmt(ctx context.Context, sctx sessionctx.Context, s sqlexec.Statement)
 			logutil.BgLogger().Error("get txn failed", zap.Error(err1))
 		}
 	}
-	err = finishStmt(ctx, sctx, se, sessVars, err)
+	err = finishStmt(ctx, sctx, se, sessVars, err, s)
 
 	if se.txn.pending() {
 		// After run statement finish, txn state is still pending means the