Add get_lock() and key_column_usage table

evaluator/builtin.go

@@ -120,6 +120,12 @@ var Funcs = map[string]Func{
 	"ifnull": {builtinIfNull, 2, 2},
 	"nullif": {builtinNullIf, 2, 2},
 
+	// miscellaneous functions
+	// get_lock() and release_lock() is parsed but do nothing.
+	// It is used for preventing error in Ruby's activerecord migrations.
+	"get_lock":     {builtinLock, 2, 2},
+	"release_lock": {builtinLock, 1, 1},
+
 	// only used by new plan
 	ast.AndAnd:     {builtinAndAnd, 2, 2},
 	ast.OrOr:       {builtinOrOr, 2, 2},

evaluator/builtin_other.go

@@ -484,3 +484,9 @@ func builtinGetVar(args []types.Datum, ctx context.Context) (types.Datum, error)
 	}
 	return types.Datum{}, nil
 }
+
+// The lock function will do nothing.
+func builtinLock(args []types.Datum, _ context.Context) (d types.Datum, err error) {
+	d.SetInt64(1)
+	return d, nil
+}

evaluator/builtin_test.go

@@ -81,3 +81,15 @@ func (s *testEvaluatorSuite) TestIsNullFunc(c *C) {
 	c.Assert(err, IsNil)
 	c.Assert(v.GetInt64(), Equals, int64(1))
 }
+
+func (s *testEvaluatorSuite) TestLock(c *C) {
+	defer testleak.AfterTest(c)()
+
+	v, err := builtinLock(types.MakeDatums(1), nil)
+	c.Assert(err, IsNil)
+	c.Assert(v.GetInt64(), Equals, int64(1))
+
+	v, err = builtinLock(types.MakeDatums(nil), nil)
+	c.Assert(err, IsNil)
+	c.Assert(v.GetInt64(), Equals, int64(1))
+}

infoschema/tables.go

@@ -37,6 +37,7 @@ const (
 	catalogVal         = "def"
 	tableProfiling     = "PROFILING"
 	tablePartitions    = "PARTITIONS"
+	tableKeyColumm     = "KEY_COLUMN_USAGE"
 )
 
 type columnInfo struct {
@@ -197,6 +198,21 @@ var collationsCols = []columnInfo{
 	{"SORTLEN", mysql.TypeLonglong, 3, 0, nil, nil},
 }
 
+var keyColumnUsageCols = []columnInfo{
+	{"CONSTRAINT_CATALOG", mysql.TypeVarchar, 512, mysql.NotNullFlag, nil, nil},
+	{"CONSTRAINT_SCHEMA", mysql.TypeVarchar, 64, mysql.NotNullFlag, nil, nil},
+	{"CONSTRAINT_NAME", mysql.TypeVarchar, 64, mysql.NotNullFlag, nil, nil},
+	{"TABLE_CATALOG", mysql.TypeVarchar, 512, mysql.NotNullFlag, nil, nil},
+	{"TABLE_SCHEMA", mysql.TypeVarchar, 64, mysql.NotNullFlag, nil, nil},
+	{"TABLE_NAME", mysql.TypeVarchar, 64, mysql.NotNullFlag, nil, nil},
+	{"COLUMN_NAME", mysql.TypeVarchar, 64, mysql.NotNullFlag, nil, nil},
+	{"ORDINAL_POSITION", mysql.TypeLonglong, 10, mysql.NotNullFlag, nil, nil},
+	{"POSITION_IN_UNIQUE_CONSTRAINT", mysql.TypeLonglong, 10, 0, nil, nil},
+	{"REFERENCED_TABLE_SCHEMA", mysql.TypeVarchar, 64, 0, nil, nil},
+	{"REFERENCED_TABLE_NAME", mysql.TypeVarchar, 64, 0, nil, nil},
+	{"REFERENCED_COLUMN_NAME", mysql.TypeVarchar, 64, 0, nil, nil},
+}
+
 // See https://dev.mysql.com/doc/refman/5.7/en/partitions-table.html
 var partitionsCols = []columnInfo{
 	{"TABLE_CATALOG", mysql.TypeVarchar, 512, 0, nil, nil},
@@ -481,6 +497,7 @@ var tableNameToColumns = map[string]([]columnInfo){
 	tableFiles:         filesCols,
 	tableProfiling:     profilingCols,
 	tablePartitions:    partitionsCols,
+	tableKeyColumm:     keyColumnUsageCols,
 }
 
 func createMemoryTable(meta *model.TableInfo, alloc autoid.Allocator) (table.Table, error) {

parser/parser.y

@@ -164,6 +164,7 @@ import (
 	full		"FULL"
 	fulltext	"FULLTEXT"
 	ge		">="
+	getLock		"GET_LOCK"
 	global		"GLOBAL"
 	grant		"GRANT"
 	grants		"GRANTS"
@@ -247,6 +248,7 @@ import (
 	redundant	"REDUNDANT"
 	references	"REFERENCES"
 	regexpKwd	"REGEXP"
+	releaseLock	"RELEASE_LOCK"
 	repeat		"REPEAT"
 	repeatable	"REPEATABLE"
 	replace		"REPLACE"
@@ -1966,7 +1968,7 @@ NotKeywordToken:
 |	"IFNULL" | "ISNULL" | "LAST_INSERT_ID" | "LCASE" | "LENGTH" | "LOCATE" | "LOWER" | "LTRIM" | "MAX" | "MICROSECOND" | "MIN"
 |	"MINUTE" | "NULLIF" | "MONTH" | "MONTHNAME" | "NOW" | "POW" | "POWER" | "RAND" | "SECOND" | "SQL_CALC_FOUND_ROWS" | "SUBDATE"
 |	"SUBSTRING" %prec lowerThanLeftParen | "SUBSTRING_INDEX" | "SUM" | "TRIM" | "RTRIM" | "UCASE" | "UPPER" | "VERSION"
-|	"WEEKDAY" | "WEEKOFYEAR" | "YEARWEEK" | "ROUND" | "STATS_PERSISTENT"
+|	"WEEKDAY" | "WEEKOFYEAR" | "YEARWEEK" | "ROUND" | "STATS_PERSISTENT" | "GET_LOCK" | "RELEASE_LOCK"
 
 /************************************************************************************
  *
@@ -2765,6 +2767,14 @@ FunctionCallNonKeyword:
 	{
 		$$ = &ast.FuncCallExpr{FnName: model.NewCIStr($1.(string)), Args: $3.([]ast.ExprNode)}
 	}
+|	"GET_LOCK" '(' Expression ',' Expression ')' 
+	{
+		$$ = &ast.FuncCallExpr{FnName: model.NewCIStr($1.(string)), Args: []ast.ExprNode{$3.(ast.ExprNode), $5.(ast.ExprNode)}}
+	}
+|	"RELEASE_LOCK" '(' Expression ')' 
+	{
+		$$ = &ast.FuncCallExpr{FnName: model.NewCIStr($1.(string)), Args: []ast.ExprNode{$3.(ast.ExprNode)}}
+	}
 
 DateArithOpt:
 	"DATE_ADD"

parser/parser_test.go

@@ -48,7 +48,7 @@ func (s *testParserSuite) TestSimple(c *C) {
 		"delay_key_write", "isolation", "repeatable", "committed", "uncommitted", "only", "serializable", "level",
 		"curtime", "variables", "dayname", "version", "btree", "hash", "row_format", "dynamic", "fixed", "compressed",
 		"compact", "redundant", "sql_no_cache sql_no_cache", "sql_cache sql_cache", "action", "round",
-		"enable", "disable", "reverse", "space", "privileges",
+		"enable", "disable", "reverse", "space", "privileges", "get_lock", "release_lock",
 	}
 	for _, kw := range unreservedKws {
 		src := fmt.Sprintf("SELECT %s FROM tbl;", kw)
@@ -618,6 +618,10 @@ func (s *testParserSuite) TestBuiltin(c *C) {
 		{`select adddate("2011-11-11 10:10:10.123456", 10)`, true},
 		{`select adddate("2011-11-11 10:10:10.123456", 0.10)`, true},
 		{`select adddate("2011-11-11 10:10:10.123456", "11,11")`, true},
+
+		// For misc functions
+		{`SELECT GET_LOCK('lock1',10);`, true},
+		{`SELECT RELEASE_LOCK('lock1');`, true},
 	}
 	s.RunTest(c, table)
 }

parser/scanner.l

@@ -378,6 +378,7 @@ found_rows	{f}{o}{u}{n}{d}_{r}{o}{w}{s}
 from		{f}{r}{o}{m}
 full		{f}{u}{l}{l}
 fulltext	{f}{u}{l}{l}{t}{e}{x}{t}
+get_lock	{g}{e}{t}_{l}{o}{c}{k}
 global		{g}{l}{o}{b}{a}{l}
 grant		{g}{r}{a}{n}{t}
 grants		{g}{r}{a}{n}{t}{s}
@@ -447,6 +448,7 @@ quarter		{q}{u}{a}{r}{t}{e}{r}
 quick		{q}{u}{i}{c}{k}
 rand		{r}{a}{n}{d}
 read		{r}{e}{a}{d}
+release_lock	{r}{e}{l}{e}{a}{s}{e}_{l}{o}{c}{k}
 repeat		{r}{e}{p}{e}{a}{t}
 repeatable	{r}{e}{p}{e}{a}{t}{a}{b}{l}{e}
 references	{r}{e}{f}{e}{r}{e}{n}{c}{e}{s}
@@ -985,11 +987,15 @@ redundant		lval.item = string(l.val)
 			return statsPersistent
 {status}		lval.item = string(l.val)
 			return status
+{get_lock}		lval.item = string(l.val)
+			return getLock
 {global}		lval.item = string(l.val)
 			return global
 {rand}			lval.item = string(l.val)
 			return rand
 {read}			return read
+{release_lock}		lval.item = string(l.val)
+			return releaseLock
 {repeat}		lval.item = string(l.val)
 			return repeat
 {repeatable}		lval.item = string(l.val)

plan/typeinferer.go

@@ -298,6 +298,8 @@ func (v *typeInferrer) handleFuncCallExpr(x *ast.FuncCallExpr) {
 		// expr2 or expr3 returns a floating-point value	floating-point
 		// expr2 or expr3 returns an integer	integer
 		tp = x.Args[1].GetType()
+	case "get_lock", "release_lock":
+		tp = types.NewFieldType(mysql.TypeLonglong)
 	default:
 		tp = types.NewFieldType(mysql.TypeUnspecified)
 	}