ddl, planner: make partition table consider collation in create table and select sentence

ddl/db_partition_test.go

@@ -43,6 +43,7 @@ import (
 	"github.com/pingcap/tidb/tablecodec"
 	"github.com/pingcap/tidb/types"
 	"github.com/pingcap/tidb/util/admin"
+	"github.com/pingcap/tidb/util/collate"
 	"github.com/pingcap/tidb/util/mock"
 	"github.com/pingcap/tidb/util/testkit"
 )
@@ -355,7 +356,9 @@ func (s *testIntegrationSuite2) TestCreateTableWithHashPartition(c *C) {
 	tk.MustExec("create table t2 (a date, b datetime) partition by hash (EXTRACT(YEAR_MONTH FROM a)) partitions 7")
 }
 
-func (s *testIntegrationSuite1) TestCreateTableWithRangeColumnPartition(c *C) {
+func (s *testIntegrationSuite7) TestCreateTableWithRangeColumnPartition(c *C) {
+	collate.SetNewCollationEnabledForTest(true)
+	defer collate.SetNewCollationEnabledForTest(false)
 	tk := testkit.NewTestKit(c, s.store)
 	tk.MustExec("use test;")
 	tk.MustExec("drop table if exists log_message_1;")
@@ -476,6 +479,13 @@ create table log_message_1 (
 				"PARTITION p1 VALUES LESS THAN (20190906));",
 			ddl.ErrWrongTypeColumnValue,
 		},
+		{
+			"create table t(a char(10) collate utf8mb4_bin) " +
+				"partition by range columns (a) (" +
+				"partition p0 values less than ('a'), " +
+				"partition p1 values less than ('G'));",
+			ddl.ErrRangeNotIncreasing,
+		},
 	}
 	for i, t := range cases {
 		_, err := tk.Exec(t.sql)
@@ -485,13 +495,25 @@ create table log_message_1 (
 		))
 	}
 
+	tk.MustExec("drop table if exists t1;")
 	tk.MustExec("create table t1 (a int, b char(3)) partition by range columns (a, b) (" +
 		"partition p0 values less than (1, 'a')," +
 		"partition p1 values less than (2, maxvalue))")
 
+	tk.MustExec("drop table if exists t2;")
 	tk.MustExec("create table t2 (a int, b char(3)) partition by range columns (b) (" +
 		"partition p0 values less than ( 'a')," +
 		"partition p1 values less than (maxvalue))")
+
+	tk.MustExec("drop table if exists t;")
+	tk.MustExec(`create table t(a char(10) collate utf8mb4_unicode_ci) partition by range columns (a) (
+    	partition p0 values less than ('a'),
+    	partition p1 values less than ('G'));`)
+
+	tk.MustExec("drop table if exists t;")
+	tk.MustExec(`create table t(a int) partition by range columns (a) (
+    	partition p0 values less than (10),
+    	partition p1 values less than (20));`)
 }
 
 func (s *testIntegrationSuite1) TestCreateTableWithListPartition(c *C) {

ddl/ddl_api.go

@@ -2121,7 +2121,8 @@ func checkTwoRangeColumns(ctx sessionctx.Context, curr, prev *model.PartitionDef
 		// PARTITION p0 VALUES LESS THAN (5,10,'ggg')
 		// PARTITION p1 VALUES LESS THAN (10,20,'mmm')
 		// PARTITION p2 VALUES LESS THAN (15,30,'sss')
-		succ, err := parseAndEvalBoolExpr(ctx, fmt.Sprintf("(%s) > (%s)", curr.LessThan[i], prev.LessThan[i]), tbInfo)
+		colInfo := findColumnByName(pi.Columns[i].L, tbInfo)
+		succ, err := parseAndEvalBoolExpr(ctx, curr.LessThan[i], prev.LessThan[i], colInfo.Collate, tbInfo)
 		if err != nil {
 			return false, err
 		}
@@ -2133,11 +2134,20 @@ func checkTwoRangeColumns(ctx sessionctx.Context, curr, prev *model.PartitionDef
 	return false, nil
 }
 
-func parseAndEvalBoolExpr(ctx sessionctx.Context, expr string, tbInfo *model.TableInfo) (bool, error) {
-	e, err := expression.ParseSimpleExprWithTableInfo(ctx, expr, tbInfo)
+func parseAndEvalBoolExpr(ctx sessionctx.Context, l, r string, coll string, tbInfo *model.TableInfo) (bool, error) {
+	lexpr, err := expression.ParseSimpleExprWithTableInfo(ctx, l, tbInfo)
 	if err != nil {
 		return false, err
 	}
+	rexpr, err := expression.ParseSimpleExprWithTableInfo(ctx, r, tbInfo)
+	if err != nil {
+		return false, err
+	}
+	e, err := expression.NewFunctionBase(ctx, ast.GT, types.NewFieldType(mysql.TypeLonglong), lexpr, rexpr)
+	if err != nil {
+		return false, err
+	}
+	e.SetCharsetAndCollation("", coll)
 	res, _, err1 := e.EvalInt(ctx, chunk.Row{})
 	if err1 != nil {
 		return false, err1

ddl/partition.go

@@ -327,11 +327,6 @@ func buildTablePartitionInfo(ctx sessionctx.Context, s *ast.CreateTableStmt) (*m
 		}
 		pi.Expr = buf.String()
 	} else if s.Partition.ColumnNames != nil {
-		// TODO: Support multiple columns for 'PARTITION BY RANGE COLUMNS'.
-		if s.Partition.Tp == model.PartitionTypeRange && len(s.Partition.ColumnNames) != 1 {
-			pi.Enable = false
-			ctx.GetSessionVars().StmtCtx.AppendWarning(ErrUnsupportedPartitionByRangeColumns)
-		}
 		pi.Columns = make([]model.CIStr, 0, len(s.Partition.ColumnNames))
 		for _, cn := range s.Partition.ColumnNames {
 			pi.Columns = append(pi.Columns, cn.Name)

planner/core/partition_pruning_test.go

@@ -21,10 +21,11 @@ import (
 	"github.com/pingcap/tidb/expression"
 	"github.com/pingcap/tidb/sessionctx"
 	"github.com/pingcap/tidb/types"
+	"github.com/pingcap/tidb/util/collate"
 	"github.com/pingcap/tidb/util/mock"
 )
 
-var _ = Suite(&testPartitionPruningSuite{})
+var _ = SerialSuites(&testPartitionPruningSuite{})
 
 type testPartitionPruningSuite struct {
 	partitionProcessor
@@ -315,6 +316,52 @@ func (s *testPartitionPruningSuite) TestPartitionRangePrunner2VarChar(c *C) {
 	}
 }
 
+func (s *testPartitionPruningSuite) TestPartitionRangePrunner2CharWithCollation(c *C) {
+	collate.SetNewCollationEnabledForTest(true)
+	defer collate.SetNewCollationEnabledForTest(false)
+	tc := prepareTestCtx(c,
+		"create table t (a char(32) collate utf8mb4_unicode_ci)",
+		"a",
+	)
+	lessThanDataInt := []string{"'c'", "'F'", "'h'", "'L'", "'t'"}
+	lessThan := make([]expression.Expression, len(lessThanDataInt)+1) // +1 for maxvalue
+	for i, str := range lessThanDataInt {
+		tmp, err := expression.ParseSimpleExprsWithNames(tc.sctx, str, tc.schema, tc.names)
+		c.Assert(err, IsNil)
+		lessThan[i] = tmp[0]
+	}
+
+	prunner := &rangeColumnsPruner{lessThan, tc.columns[0], true}
+	cases := []struct {
+		input  string
+		result partitionRangeOR
+	}{
+		{"a > 'G'", partitionRangeOR{{2, 6}}},
+		{"a > 'g'", partitionRangeOR{{2, 6}}},
+		{"a < 'h'", partitionRangeOR{{0, 3}}},
+		{"a >= 'M'", partitionRangeOR{{4, 6}}},
+		{"a > 'm'", partitionRangeOR{{4, 6}}},
+		{"a < 'F'", partitionRangeOR{{0, 2}}},
+		{"a = 'C'", partitionRangeOR{{1, 2}}},
+		{"a > 't'", partitionRangeOR{{5, 6}}},
+		{"a > 'C' and a < 'q'", partitionRangeOR{{1, 5}}},
+		{"a > 'c' and a < 'Q'", partitionRangeOR{{1, 5}}},
+		{"a < 'l' or a >= 'W'", partitionRangeOR{{0, 4}, {5, 6}}},
+		{"a is null", partitionRangeOR{{0, 1}}},
+		{"'Mm' > a", partitionRangeOR{{0, 5}}},
+		{"'f' <= a", partitionRangeOR{{2, 6}}},
+		{"'f' >= a", partitionRangeOR{{0, 3}}},
+	}
+
+	for _, ca := range cases {
+		expr, err := expression.ParseSimpleExprsWithNames(tc.sctx, ca.input, tc.schema, tc.names)
+		c.Assert(err, IsNil)
+		result := fullRange(len(lessThan))
+		result = partitionRangeForExpr(tc.sctx, expr[0], prunner, result)
+		c.Assert(equalPartitionRangeOR(ca.result, result), IsTrue, Commentf("unexpected:", ca.input))
+	}
+}
+
 func (s *testPartitionPruningSuite) TestPartitionRangePrunner2Date(c *C) {
 	tc := prepareTestCtx(c,
 		"create table t (a date)",

planner/core/rule_partition_processor.go

@@ -1155,11 +1155,12 @@ func (p *rangeColumnsPruner) partitionRangeForExpr(sctx sessionctx.Context, expr
 		return 0, len(p.data), false
 	}
 
-	start, end := p.pruneUseBinarySearch(sctx, opName, con)
+	_, collation := op.CharsetAndCollation(sctx)
+	start, end := p.pruneUseBinarySearch(sctx, opName, con, collation)
 	return start, end, true
 }
 
-func (p *rangeColumnsPruner) pruneUseBinarySearch(sctx sessionctx.Context, op string, data *expression.Constant) (start int, end int) {
+func (p *rangeColumnsPruner) pruneUseBinarySearch(sctx sessionctx.Context, op string, data *expression.Constant, collation string) (start int, end int) {
 	var err error
 	var isNull bool
 	compare := func(ith int, op string, v *expression.Constant) bool {
@@ -1169,7 +1170,8 @@ func (p *rangeColumnsPruner) pruneUseBinarySearch(sctx sessionctx.Context, op st
 			}
 		}
 		var expr expression.Expression
-		expr, err = expression.NewFunction(sctx, op, types.NewFieldType(mysql.TypeLonglong), p.data[ith], v)
+		expr, err = expression.NewFunctionBase(sctx, op, types.NewFieldType(mysql.TypeLonglong), p.data[ith], v)
+		expr.SetCharsetAndCollation("", collation)
 		var val int64
 		val, isNull, err = expr.EvalInt(sctx, chunk.Row{})
 		return val > 0