fix bug: when the updated data does not change, there is no need to c…

…heck the constraints (#12753) …check the constraints (#12732) fix bug: when the updated data does not change, there is no need to check the constraints you can repro like: ``` create table f1 (a int primary key); create table c1(aa int primary key, bb int, CONSTRAINT `fk_bb` FOREIGN KEY (`bb`) REFERENCES `f1`(`a`)); insert into f1 values (1); insert into c1 values (1,1); update f1 set a=a; //MO throw error. but MySQL not. this PR will fix it ``` Approved by: @heni02, @badboynt1, @aunjgr
matrixorigin · Nov 15, 2023 · 79ee4c1 · 79ee4c1
1 parent efb87f6
commit 79ee4c1
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Showing 3 changed files with 88 additions and 5 deletions.
diff --git a/pkg/sql/plan/build_dml_util.go b/pkg/sql/plan/build_dml_util.go
@@ -422,16 +422,15 @@ func buildDeletePlans(ctx CompilerContext, builder *QueryBuilder, bindCtx *BindC
 			for _, fk := range childTableDef.Fkeys {
 				if fk.ForeignTbl == delCtx.tableDef.TblId {
 					// update stmt: update the columns do not contain ref key, skip
+					updateRefColumn := make(map[string]int32)
 					if isUpdate {
-						updateRefColumn := false
 						for _, colId := range fk.ForeignCols {
 							updateName := idNameMap[colId]
-							if _, ok := delCtx.updateColPosMap[updateName]; ok {
-								updateRefColumn = true
-								break
+							if uIdx, ok := delCtx.updateColPosMap[updateName]; ok {
+								updateRefColumn[updateName] = int32(uIdx)
 							}
 						}
-						if !updateRefColumn {
+						if len(updateRefColumn) == 0 {
 							continue
 						}
 					}
@@ -529,6 +528,46 @@ func buildDeletePlans(ctx CompilerContext, builder *QueryBuilder, bindCtx *BindC
 					}
 
 					lastNodeId = appendSinkScanNode(builder, bindCtx, delCtx.sourceStep)
+					// deal with case:  update t1 set a = a.  then do not need to check constraint
+					if isUpdate {
+						var filterExpr, tmpExpr *Expr
+						for updateName, newIdx := range updateRefColumn {
+							oldIdx := nameIdxMap[updateName]
+							tmpExpr, err = bindFuncExprImplByPlanExpr(builder.GetContext(), "!=", []*Expr{{
+								Typ: nameTypMap[updateName],
+								Expr: &plan.Expr_Col{
+									Col: &ColRef{
+										ColPos: oldIdx,
+										Name:   updateName,
+									},
+								},
+							}, {
+								Typ: nameTypMap[updateName],
+								Expr: &plan.Expr_Col{
+									Col: &ColRef{
+										ColPos: newIdx,
+										Name:   updateName,
+									},
+								},
+							}})
+							if err != nil {
+								return nil
+							}
+							if filterExpr == nil {
+								filterExpr = tmpExpr
+							} else {
+								filterExpr, err = bindFuncExprImplByPlanExpr(builder.GetContext(), "or", []*Expr{filterExpr, tmpExpr})
+								if err != nil {
+									return nil
+								}
+							}
+						}
+						lastNodeId = builder.appendNode(&plan.Node{
+							NodeType:   plan.Node_FILTER,
+							Children:   []int32{lastNodeId},
+							FilterList: []*Expr{filterExpr},
+						}, bindCtx)
+					}
 
 					switch refAction {
 					case plan.ForeignKeyDef_NO_ACTION, plan.ForeignKeyDef_RESTRICT, plan.ForeignKeyDef_SET_DEFAULT:

diff --git a/test/distributed/cases/foreign_key/fk_base.result b/test/distributed/cases/foreign_key/fk_base.result
@@ -320,6 +320,28 @@ drop table fk_04;
 drop table fk_03;
 drop table fk_02;
 drop table fk_01;
+create table f1(a int, b int, primary key (a,b));
+create table c1(id int primary key, aa int, bb int, CONSTRAINT `fk_aa` FOREIGN KEY(`aa`) REFERENCES `f1`(`a`));
+insert into f1 values (1,1);
+insert into c1 values (1,1,1);
+update f1 set a=a;
+update f1 set a=1;
+update f1 set a=a, b=2;
+update f1 set a=2;
+internal error: Cannot delete or update a parent row: a foreign key constraint fails
+drop table c1;
+drop table f1;
+create table f1(a int, b int, primary key (a,b));
+create table c1(id int primary key, aa int, bb int, CONSTRAINT `fk_aa` FOREIGN KEY(`aa`,`bb`) REFERENCES `f1`(`a`,`b`));
+insert into f1 values (1,1);
+insert into c1 values (1,1,1);
+update f1 set a=a;
+update f1 set a=a, b=1;
+update f1 set b=1, a=a;
+update f1 set a=a, b=2;
+internal error: Cannot delete or update a parent row: a foreign key constraint fails
+drop table c1;
+drop table f1;
 drop database if exists db1;
 create database db1;
 use db1;

diff --git a/test/distributed/cases/foreign_key/fk_base.sql b/test/distributed/cases/foreign_key/fk_base.sql
@@ -238,6 +238,28 @@ drop table fk_03;
 drop table fk_02;
 drop table fk_01;
 
+create table f1(a int, b int, primary key (a,b));
+create table c1(id int primary key, aa int, bb int, CONSTRAINT `fk_aa` FOREIGN KEY(`aa`) REFERENCES `f1`(`a`));
+insert into f1 values (1,1);
+insert into c1 values (1,1,1);
+update f1 set a=a;
+update f1 set a=1;
+update f1 set a=a, b=2;
+update f1 set a=2;
+drop table c1;
+drop table f1;
+
+create table f1(a int, b int, primary key (a,b));
+create table c1(id int primary key, aa int, bb int, CONSTRAINT `fk_aa` FOREIGN KEY(`aa`,`bb`) REFERENCES `f1`(`a`,`b`));
+insert into f1 values (1,1);
+insert into c1 values (1,1,1);
+update f1 set a=a;
+update f1 set a=a, b=1;
+update f1 set b=1, a=a;
+update f1 set a=a, b=2;
+drop table c1;
+drop table f1;
+
 drop database if exists db1;
 create database db1;
 use db1;