Merge branch 'release-2.1' into release-2.1-pingcap#8442

executor/prepared_test.go

@@ -199,6 +199,20 @@ func (s *testSuite) TestPrepared(c *C) {
 		c.Assert(err, IsNil)
 		c.Assert(len(fields), Equals, 0)
 
+		// issue 8074
+		tk.MustExec("drop table if exists prepare1;")
+		tk.MustExec("create table prepare1 (a decimal(1))")
+		tk.MustExec("insert into prepare1 values(1);")
+		_, err = tk.Exec("prepare stmt FROM @sql1")
+		c.Assert(err.Error(), Equals, "line 1 column 4 near \"\" (total length 4)")
+		tk.MustExec("SET @sql = 'update prepare1 set a=5 where a=?';")
+		_, err = tk.Exec("prepare stmt FROM @sql")
+		c.Assert(err, IsNil)
+		tk.MustExec("set @var=1;")
+		_, err = tk.Exec("execute stmt using @var")
+		c.Assert(err, IsNil)
+		tk.MustQuery("select a from prepare1;").Check(testkit.Rows("5"))
+
 		// Coverage.
 		exec := &executor.ExecuteExec{}
 		exec.Next(ctx, nil)

planner/core/planbuilder.go

@@ -115,7 +115,7 @@ type planBuilder struct {
 	inUpdateStmt bool
 	// colMapper stores the column that must be pre-resolved.
 	colMapper map[*ast.ColumnNameExpr]int
-	// Collect the visit information for privilege check.
+	// visitInfo the visit information for privilege check.
 	visitInfo     []visitInfo
 	tableHintInfo []tableHintInfo
 	optFlag       uint64
@@ -248,7 +248,7 @@ func (b *planBuilder) buildSet(v *ast.SetStmt) (Plan, error) {
 	return p, nil
 }
 
-// Detect aggregate function or groupby clause.
+// detectSelectAgg detect aggregate function or groupby clause.
 func (b *planBuilder) detectSelectAgg(sel *ast.SelectStmt) bool {
 	if sel.GroupBy != nil {
 		return true
@@ -377,8 +377,11 @@ func (b *planBuilder) buildPrepare(x *ast.PrepareStmt) Plan {
 		Name: x.Name,
 	}
 	if x.SQLVar != nil {
-		// TODO: Prepared statement from variable expression do not work as expected.
-		// p.SQLText, _ = x.SQLVar.GetValue().(string)
+		if v, ok := b.ctx.GetSessionVars().Users[x.SQLVar.Name]; ok {
+			p.SQLText = v
+		} else {
+			p.SQLText = "NULL"
+		}
 	} else {
 		p.SQLText = x.SQLText
 	}