*: modify the printing of column default expression in `SHOW CREATE T…

…ABLE` and `Restore` (#52940) close #52939
pingcap · Apr 28, 2024 · 66ba419 · 66ba419
1 parent 0412aa1
commit 66ba419
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Showing 10 changed files with 6,284 additions and 6,245 deletions.
diff --git a/pkg/ddl/db_integration_test.go b/pkg/ddl/db_integration_test.go
@@ -1593,17 +1593,17 @@ func TestDefaultColumnWithRand(t *testing.T) {
 	tk.MustQuery("show create table t").Check(testkit.Rows(
 		"t CREATE TABLE `t` (\n" +
 			"  `c` int(10) DEFAULT NULL,\n" +
-			"  `c1` int(11) DEFAULT rand()\n" +
+			"  `c1` int(11) DEFAULT (rand())\n" +
 			") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin"))
 	tk.MustQuery("show create table t1").Check(testkit.Rows(
 		"t1 CREATE TABLE `t1` (\n" +
 			"  `c` int(11) DEFAULT NULL,\n" +
-			"  `c1` double DEFAULT rand()\n" +
+			"  `c1` double DEFAULT (rand())\n" +
 			") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin"))
 	tk.MustQuery("show create table t2").Check(testkit.Rows(
 		"t2 CREATE TABLE `t2` (\n" +
 			"  `c` int(11) DEFAULT NULL,\n" +
-			"  `c1` double DEFAULT rand(1)\n" +
+			"  `c1` double DEFAULT (rand(1))\n" +
 			") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin"))
 
 	// use a non-existent function name

diff --git a/pkg/executor/show.go b/pkg/executor/show.go
@@ -1032,12 +1032,19 @@ func constructResultOfShowCreateTable(ctx sessionctx.Context, dbName *model.CISt
 						}
 						buf.WriteString(" DEFAULT NULL")
 					}
-				case "CURRENT_TIMESTAMP", "CURRENT_DATE":
+				case "CURRENT_TIMESTAMP":
 					buf.WriteString(" DEFAULT ")
 					buf.WriteString(defaultValue.(string))
 					if col.GetDecimal() > 0 {
 						fmt.Fprintf(buf, "(%d)", col.GetDecimal())
 					}
+				case "CURRENT_DATE":
+					buf.WriteString(" DEFAULT (")
+					buf.WriteString(defaultValue.(string))
+					if col.GetDecimal() > 0 {
+						fmt.Fprintf(buf, "(%d)", col.GetDecimal())
+					}
+					buf.WriteString(")")
 				default:
 					defaultValStr := fmt.Sprintf("%v", defaultValue)
 					// If column is timestamp, and default value is not current_timestamp, should convert the default value to the current session time zone.
@@ -1050,7 +1057,7 @@ func constructResultOfShowCreateTable(ctx sessionctx.Context, dbName *model.CISt
 					}
 
 					if col.DefaultIsExpr {
-						fmt.Fprintf(buf, " DEFAULT %s", defaultValStr)
+						fmt.Fprintf(buf, " DEFAULT (%s)", defaultValStr)
 					} else {
 						if col.GetType() == mysql.TypeBit {
 							defaultValBinaryLiteral := types.BinaryLiteral(defaultValStr)

diff --git a/pkg/parser/ast/ddl.go b/pkg/parser/ast/ddl.go
@@ -579,9 +579,21 @@ func (n *ColumnOption) Restore(ctx *format.RestoreCtx) error {
 		ctx.WriteKeyWord("AUTO_INCREMENT")
 	case ColumnOptionDefaultValue:
 		ctx.WriteKeyWord("DEFAULT ")
+		printOuterParentheses := false
+		if funcCallExpr, ok := n.Expr.(*FuncCallExpr); ok {
+			if name := funcCallExpr.FnName.L; name != CurrentTimestamp {
+				printOuterParentheses = true
+			}
+		}
+		if printOuterParentheses {
+			ctx.WritePlain("(")
+		}
 		if err := n.Expr.Restore(ctx); err != nil {
 			return errors.Annotate(err, "An error occurred while splicing ColumnOption DefaultValue Expr")
 		}
+		if printOuterParentheses {
+			ctx.WritePlain(")")
+		}
 	case ColumnOptionUniqKey:
 		ctx.WriteKeyWord("UNIQUE KEY")
 	case ColumnOptionNull: