expression: rewrite builtin function: FIND_IN_SET (#4247)

pingcap · Aug 21, 2017 · acff4b6 · acff4b6
1 parent 31edc09
commit acff4b6
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Showing 4 changed files with 49 additions and 28 deletions.
diff --git a/expression/builtin_string.go b/expression/builtin_string.go
@@ -1999,49 +1999,46 @@ func (c *findInSetFunctionClass) getFunction(args []Expression, ctx context.Cont
 	if err := c.verifyArgs(args); err != nil {
 		return nil, errors.Trace(err)
 	}
-	sig := &builtinFindInSetSig{newBaseBuiltinFunc(args, ctx)}
+	bf, err := newBaseBuiltinFuncWithTp(args, ctx, tpInt, tpString, tpString)
+	if err != nil {
+		return nil, errors.Trace(err)
+	}
+	bf.tp.Flen = 3
+	sig := &builtinFindInSetSig{baseIntBuiltinFunc{bf}}
 	return sig.setSelf(sig), nil
 }
 
 type builtinFindInSetSig struct {
-	baseBuiltinFunc
+	baseIntBuiltinFunc
 }
 
-// eval evals a builtinFindInSetSig.
+// evalInt evals FIND_IN_SET(str,strlist).
 // See https://dev.mysql.com/doc/refman/5.7/en/string-functions.html#function_find-in-set
 // TODO: This function can be optimized by using bit arithmetic when the first argument is
 // a constant string and the second is a column of type SET.
-func (b *builtinFindInSetSig) eval(row []types.Datum) (d types.Datum, err error) {
-	args, err := b.evalArgs(row)
-	if err != nil {
-		return types.Datum{}, errors.Trace(err)
-	}
-	// args[0] -> Str
-	// args[1] -> StrList
-	if args[0].IsNull() || args[1].IsNull() {
-		return
-	}
+func (b *builtinFindInSetSig) evalInt(row []types.Datum) (int64, bool, error) {
+	sc := b.ctx.GetSessionVars().StmtCtx
 
-	str, err := args[0].ToString()
-	if err != nil {
-		return d, errors.Trace(err)
+	str, isNull, err := b.args[0].EvalString(row, sc)
+	if isNull || err != nil {
+		return 0, isNull, errors.Trace(err)
 	}
-	strlst, err := args[1].ToString()
-	if err != nil {
-		return d, errors.Trace(err)
+
+	strlist, isNull, err := b.args[1].EvalString(row, sc)
+	if isNull || err != nil {
+		return 0, isNull, errors.Trace(err)
 	}
 
-	d.SetInt64(0)
-	if len(strlst) == 0 {
-		return
+	if len(strlist) == 0 {
+		return 0, false, nil
 	}
-	for i, s := range strings.Split(strlst, ",") {
-		if s == str {
-			d.SetInt64(int64(i + 1))
-			return
+
+	for i, strInSet := range strings.Split(strlist, ",") {
+		if str == strInSet {
+			return int64(i + 1), false, nil
 		}
 	}
-	return
+	return 0, false, nil
 }
 
 type fieldFunctionClass struct {

diff --git a/expression/builtin_string_test.go b/expression/builtin_string_test.go
@@ -1185,9 +1185,10 @@ func (s *testEvaluatorSuite) TestFindInSet(c *C) {
 		fc := funcs[ast.FindInSet]
 		f, err := fc.getFunction(datumsToConstants(types.MakeDatums(t.str, t.strlst)), s.ctx)
 		c.Assert(err, IsNil)
+		c.Assert(f.isDeterministic(), IsTrue)
 		r, err := f.eval(nil)
 		c.Assert(err, IsNil)
-		c.Assert(r, testutil.DatumEquals, types.NewDatum(t.ret))
+		c.Assert(r, testutil.DatumEquals, types.NewDatum(t.ret), Commentf("FindInSet(%s, %s)", t.str, t.strlst))
 	}
 }
 

diff --git a/expression/integration_test.go b/expression/integration_test.go
@@ -792,6 +792,12 @@ func (s *testIntegrationSuite) TestStringBuiltin(c *C) {
 	result.Check(testkit.Rows("0 1777777777777777777777 1777777777777777777777 1777777777777777777777"))
 	result = tk.MustQuery(`select oct(-1.9), oct(1.9), oct(-1), oct(1), oct(-9999999999999999999999999), oct(9999999999999999999999999);`)
 	result.Check(testkit.Rows("1777777777777777777777 1 1777777777777777777777 1 1777777777777777777777 1777777777777777777777"))
+
+	// for find_in_set
+	result = tk.MustQuery(`select find_in_set("", ""), find_in_set("", ","), find_in_set("中文", "字符串,中文"), find_in_set("b,", "a,b,c,d");`)
+	result.Check(testkit.Rows("0 1 2 0"))
+	result = tk.MustQuery(`select find_in_set(NULL, ""), find_in_set("", NULL), find_in_set(1, "2,3,1");`)
+	result.Check(testkit.Rows("<nil> <nil> 3"))
 }
 
 func (s *testIntegrationSuite) TestEncryptionBuiltin(c *C) {

diff --git a/plan/typeinfer_test.go b/plan/typeinfer_test.go
@@ -328,6 +328,23 @@ func (s *testPlanSuite) createTestCase4StrFuncs() []typeInferTestCase {
 		{"oct(c_blob     )", mysql.TypeVarString, charset.CharsetUTF8, 0, 64, types.UnspecifiedLength},
 		{"oct(c_set      )", mysql.TypeVarString, charset.CharsetUTF8, 0, 64, types.UnspecifiedLength},
 		{"oct(c_enum     )", mysql.TypeVarString, charset.CharsetUTF8, 0, 64, types.UnspecifiedLength},
+
+		{"find_in_set(c_int      , c_text)", mysql.TypeLonglong, charset.CharsetBin, mysql.BinaryFlag, 3, 0},
+		{"find_in_set(c_bigint   , c_text)", mysql.TypeLonglong, charset.CharsetBin, mysql.BinaryFlag, 3, 0},
+		{"find_in_set(c_float    , c_text)", mysql.TypeLonglong, charset.CharsetBin, mysql.BinaryFlag, 3, 0},
+		{"find_in_set(c_double   , c_text)", mysql.TypeLonglong, charset.CharsetBin, mysql.BinaryFlag, 3, 0},
+		{"find_in_set(c_decimal  , c_text)", mysql.TypeLonglong, charset.CharsetBin, mysql.BinaryFlag, 3, 0},
+		{"find_in_set(c_datetime , c_text)", mysql.TypeLonglong, charset.CharsetBin, mysql.BinaryFlag, 3, 0},
+		{"find_in_set(c_time     , c_text)", mysql.TypeLonglong, charset.CharsetBin, mysql.BinaryFlag, 3, 0},
+		{"find_in_set(c_timestamp, c_text)", mysql.TypeLonglong, charset.CharsetBin, mysql.BinaryFlag, 3, 0},
+		{"find_in_set(c_char     , c_text)", mysql.TypeLonglong, charset.CharsetBin, mysql.BinaryFlag, 3, 0},
+		{"find_in_set(c_varchar  , c_text)", mysql.TypeLonglong, charset.CharsetBin, mysql.BinaryFlag, 3, 0},
+		{"find_in_set(c_text     , c_text)", mysql.TypeLonglong, charset.CharsetBin, mysql.BinaryFlag, 3, 0},
+		{"find_in_set(c_binary   , c_text)", mysql.TypeLonglong, charset.CharsetBin, mysql.BinaryFlag, 3, 0},
+		{"find_in_set(c_varbinary, c_text)", mysql.TypeLonglong, charset.CharsetBin, mysql.BinaryFlag, 3, 0},
+		{"find_in_set(c_blob     , c_text)", mysql.TypeLonglong, charset.CharsetBin, mysql.BinaryFlag, 3, 0},
+		{"find_in_set(c_set      , c_text)", mysql.TypeLonglong, charset.CharsetBin, mysql.BinaryFlag, 3, 0},
+		{"find_in_set(c_enum     , c_text)", mysql.TypeLonglong, charset.CharsetBin, mysql.BinaryFlag, 3, 0},
 	}
 }