feat: fix translation logic to fail translation for conversions not s…

…upported (#12111) (#12118) Signed-off-by: Manan Gupta <[email protected]> Signed-off-by: Manan Gupta <[email protected]> Signed-off-by: Manan Gupta <[email protected]>
vitessio · Jan 19, 2023 · b9fd93e · b9fd93e
1 parent 9a5f084
commit b9fd93e
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Showing 4 changed files with 60 additions and 8 deletions.
diff --git a/go/test/endtoend/vtgate/misc_test.go b/go/test/endtoend/vtgate/misc_test.go
@@ -860,3 +860,18 @@ func TestIntervalWithMathFunctions(t *testing.T) {
 	utils.AssertMatches(t, conn, "select '2020-01-01' + interval month(DATE_SUB(FROM_UNIXTIME(1234), interval 1 month))-1 month", `[[CHAR("2020-12-01")]]`)
 	utils.AssertMatches(t, conn, "select DATE_ADD(MIN(FROM_UNIXTIME(1673444922)),interval -DAYOFWEEK(MIN(FROM_UNIXTIME(1673444922)))+1 DAY)", `[[DATETIME("2023-01-08 13:48:42")]]`)
 }
+
+// TestCast tests the queries that contain the cast function.
+func TestCast(t *testing.T) {
+	defer cluster.PanicHandler(t)
+	ctx := context.Background()
+	conn, err := mysql.Connect(ctx, &vtParams)
+	require.NoError(t, err)
+	defer conn.Close()
+
+	utils.AssertMatches(t, conn, "select cast('2023-01-07 12:34:56' as date) limit 1", `[[DATE("2023-01-07")]]`)
+	utils.AssertMatches(t, conn, "select cast('2023-01-07 12:34:56' as date)", `[[DATE("2023-01-07")]]`)
+	utils.AssertMatches(t, conn, "select cast('3.2' as float)", `[[FLOAT32(3.2)]]`)
+	utils.AssertMatches(t, conn, "select cast('3.2' as double)", `[[FLOAT64(3.2)]]`)
+	utils.AssertMatches(t, conn, "select cast('3.2' as unsigned)", `[[UINT64(3)]]`)
+}
diff --git a/go/vt/vtgate/evalengine/convert.go b/go/vt/vtgate/evalengine/convert.go
@@ -39,6 +39,10 @@ type (
 )
 
 func (c *ConvertExpr) unsupported() {
+	throwEvalError(c.returnUnsupportedError())
+}
+
+func (c *ConvertExpr) returnUnsupportedError() error {
 	var err error
 	switch {
 	case c.HasLength && c.HasScale:
@@ -48,7 +52,7 @@ func (c *ConvertExpr) unsupported() {
 	default:
 		err = vterrors.Errorf(vtrpcpb.Code_UNIMPLEMENTED, "Unsupported type conversion: %s", c.Type)
 	}
-	throwEvalError(err)
+	return err
 }
 
 func (c *ConvertExpr) eval(env *ExpressionEnv, result *EvalResult) {
@@ -86,15 +90,9 @@ func (c *ConvertExpr) eval(env *ExpressionEnv, result *EvalResult) {
 	case "FLOAT":
 		if c.HasLength {
 			switch p := c.Length; {
-			case p <= 24:
-				c.unsupported()
-			case p <= 53:
-				result.makeFloat()
-			default:
+			case p > 53:
 				throwEvalError(vterrors.Errorf(vtrpcpb.Code_INVALID_ARGUMENT, "Too-big precision %d specified for 'CONVERT'. Maximum is 53.", p))
 			}
-		} else {
-			c.unsupported()
 		}
 		c.unsupported()
 	case "SIGNED", "SIGNED INTEGER":

diff --git a/go/vt/vtgate/evalengine/translate.go b/go/vt/vtgate/evalengine/translate.go
@@ -487,6 +487,11 @@ func translateConvertExpr(expr sqlparser.Expr, convertType *sqlparser.ConvertTyp
 		if err != nil {
 			return nil, err
 		}
+	case "BINARY", "DOUBLE", "REAL", "SIGNED", "SIGNED INTEGER", "UNSIGNED", "UNSIGNED INTEGER":
+		// Supported types for conv expression
+	default:
+		// For unsupported types, we should return an error on translation instead of returning an error on runtime.
+		return nil, convert.returnUnsupportedError()
 	}
 
 	return &convert, nil

diff --git a/go/vt/vtgate/evalengine/translate_test.go b/go/vt/vtgate/evalengine/translate_test.go
@@ -334,3 +334,37 @@ func TestEvaluateTuple(t *testing.T) {
 		})
 	}
 }
+
+// TestTranslationFailures tests that translation fails for functions that we don't support evaluation for.
+func TestTranslationFailures(t *testing.T) {
+	testcases := []struct {
+		expression  string
+		expectedErr string
+	}{
+		{
+			expression:  "cast('2023-01-07 12:34:56' as date)",
+			expectedErr: "Unsupported type conversion: DATE",
+		}, {
+			expression:  "cast('2023-01-07 12:34:56' as datetime(5))",
+			expectedErr: "Unsupported type conversion: DATETIME(5)",
+		}, {
+			expression:  "cast('3.4' as FLOAT)",
+			expectedErr: "Unsupported type conversion: FLOAT",
+		}, {
+			expression:  "cast('3.4' as FLOAT(3))",
+			expectedErr: "Unsupported type conversion: FLOAT(3)",
+		},
+	}
+
+	for _, testcase := range testcases {
+		t.Run(testcase.expression, func(t *testing.T) {
+			// Given
+			stmt, err := sqlparser.Parse("select " + testcase.expression)
+			require.NoError(t, err)
+			astExpr := stmt.(*sqlparser.Select).SelectExprs[0].(*sqlparser.AliasedExpr).Expr
+			_, err = Translate(astExpr, LookupDefaultCollation(45))
+			require.EqualError(t, err, testcase.expectedErr)
+		})
+	}
+
+}