Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

support locking clause in select statement #6

Merged
merged 1 commit into from
Sep 9, 2024
Merged

support locking clause in select statement #6

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
60 changes: 60 additions & 0 deletions ast.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -611,6 +611,60 @@ func (t *OrderingTerm) String() string {
return buf.String()
}

type LockStrength int

const (
Update LockStrength = iota
NoKeyUpdate
Share
KeyShare
)

type LockOption int

func (l LockOption) ToPtr() *LockOption {
return &l
}

const (
Nowait LockOption = iota
SkipLocked
)

type LockingClause struct {
Strength LockStrength

Option *LockOption
}

func (c *LockingClause) String() string {
var buf bytes.Buffer
buf.Grow(30)
buf.WriteString("FOR")

switch c.Strength {
case Update:
buf.WriteString(" UPDATE")
case NoKeyUpdate:
buf.WriteString(" NO KEY UPDATE")
case Share:
buf.WriteString(" SHARE")
case KeyShare:
buf.WriteString(" KEY SHARE")
}

if c.Option != nil {
switch *c.Option {
case Nowait:
buf.WriteString(" NOWAIT")
case SkipLocked:
buf.WriteString(" SKIP LOCKED")
}
}

return buf.String()
}

type ColumnArg interface {
Node
columnArg()
Expand Down Expand Up @@ -928,6 +982,8 @@ type SelectStatement struct {
Limit Expr
Offset Expr // offset expression

Locking *LockingClause

Hint *Hint
}

Expand Down Expand Up @@ -1004,6 +1060,10 @@ func (s *SelectStatement) String() string {
}
}

if s.Locking != nil {
fmt.Fprintf(&buf, " %s", s.Locking.String())
}

return buf.String()
}

Expand Down
36 changes: 36 additions & 0 deletions ast_test.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -312,6 +312,42 @@ func TestSelectStatement_String(t *testing.T) {
Y: &sqlparser.TableName{Name: &sqlparser.Ident{Name: "y"}},
},
}, `SELECT * FROM x CROSS JOIN y`)

AssertStatementStringer(t, &sqlparser.SelectStatement{
Distinct: true,
Columns: &sqlparser.OutputNames{&sqlparser.ResultColumn{
Star: true,
}},
Condition: &sqlparser.BinaryExpr{
X: &sqlparser.Ident{Name: "ID"},
Op: sqlparser.EQ,
Y: &sqlparser.NumberLit{Value: "1"},
},
FromItems: &sqlparser.TableName{
Name: &sqlparser.Ident{Name: "tbl"},
},
Locking: &sqlparser.LockingClause{
Strength: sqlparser.Update,
Option: sqlparser.Nowait.ToPtr(),
}}, `SELECT DISTINCT * FROM tbl WHERE ID = 1 FOR UPDATE NOWAIT`)

AssertStatementStringer(t, &sqlparser.SelectStatement{
Distinct: true,
Columns: &sqlparser.OutputNames{&sqlparser.ResultColumn{
Star: true,
}},
Condition: &sqlparser.BinaryExpr{
X: &sqlparser.Ident{Name: "ID"},
Op: sqlparser.EQ,
Y: &sqlparser.NumberLit{Value: "1"},
},
FromItems: &sqlparser.TableName{
Name: &sqlparser.Ident{Name: "tbl"},
},
Locking: &sqlparser.LockingClause{
Strength: sqlparser.NoKeyUpdate,
Option: sqlparser.SkipLocked.ToPtr(),
}}, `SELECT DISTINCT * FROM tbl WHERE ID = 1 FOR NO KEY UPDATE SKIP LOCKED`)
}

func TestUpdateStatement_String(t *testing.T) {
Expand Down
50 changes: 50 additions & 0 deletions parser.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -616,6 +616,56 @@ func (p *Parser) parseSelectStatement(compounded bool) (_ *SelectStatement, err
}
}

if !compounded && p.peek() == FOR {
locking := &LockingClause{}
p.lex()
switch p.peek() {
case UPDATE:
locking.Strength = Update
p.lex()
case NO:
p.lex()
if p.peek() != KEY {
return &stmt, p.errorExpected(p.pos, p.tok, "KEY")
}
p.lex()
if p.peek() != UPDATE {
return &stmt, p.errorExpected(p.pos, p.tok, "UPDATE")
}
locking.Strength = NoKeyUpdate
p.lex()
case SHARE:
locking.Strength = Share
p.lex()
case KEY:
p.lex()
if p.peek() != SHARE {
return &stmt, p.errorExpected(p.pos, p.tok, "SHARE")
}
locking.Strength = KeyShare
p.lex()
default:
return &stmt, p.errorExpected(p.pos, p.tok, "UPDATE | NO | SHARE | KEY")
}

switch p.peek() {
case NOWAIT:
locking.Option = Nowait.ToPtr()
p.lex()
case SKIP:
p.lex()
if p.peek() != LOCKED {
return &stmt, p.errorExpected(p.pos, p.tok, "LOCKED")
}
locking.Option = SkipLocked.ToPtr()
p.lex()
default:

}

stmt.Locking = locking
}

return &stmt, nil
}

Expand Down
38 changes: 38 additions & 0 deletions parser_test.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -343,6 +343,44 @@ func TestParser_ParseStatement(t *testing.T) {
},
})

AssertParseStatement(t, `SELECT DISTINCT * FROM tbl WHERE ID = 1 FOR UPDATE NOWAIT`, &sqlparser.SelectStatement{
Distinct: true,
Columns: &sqlparser.OutputNames{&sqlparser.ResultColumn{
Star: true,
}},
Condition: &sqlparser.BinaryExpr{
X: &sqlparser.Ident{Name: "ID"},
Op: sqlparser.EQ,
Y: &sqlparser.NumberLit{Value: "1"},
},
FromItems: &sqlparser.TableName{
Name: &sqlparser.Ident{Name: "tbl"},
},
Locking: &sqlparser.LockingClause{
Strength: sqlparser.Update,
Option: sqlparser.Nowait.ToPtr(),
},
})

AssertParseStatement(t, `SELECT DISTINCT * FROM tbl WHERE ID = 1 FOR NO KEY UPDATE SKIP LOCKED`, &sqlparser.SelectStatement{
Distinct: true,
Columns: &sqlparser.OutputNames{&sqlparser.ResultColumn{
Star: true,
}},
Condition: &sqlparser.BinaryExpr{
X: &sqlparser.Ident{Name: "ID"},
Op: sqlparser.EQ,
Y: &sqlparser.NumberLit{Value: "1"},
},
FromItems: &sqlparser.TableName{
Name: &sqlparser.Ident{Name: "tbl"},
},
Locking: &sqlparser.LockingClause{
Strength: sqlparser.NoKeyUpdate,
Option: sqlparser.SkipLocked.ToPtr(),
},
})

AssertParseStatementError(t, `SELECT `, `1:7: expected expression, found 'EOF'`)
AssertParseStatementError(t, `SELECT 1+`, `1:9: expected expression, found 'EOF'`)
AssertParseStatementError(t, `SELECT foo,`, `1:11: expected expression, found 'EOF'`)
Expand Down
8 changes: 8 additions & 0 deletions token.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -234,6 +234,10 @@ const (
WITH
WITHOUT
DUPLICATE
SHARE
NOWAIT
SKIP
LOCKED
keyword_end

ANY // ???
Expand Down Expand Up @@ -446,6 +450,10 @@ var tokens = [...]string{
WITH: "WITH",
WITHOUT: "WITHOUT",
DUPLICATE: "DUPLICATE",
SHARE: "SHARE",
NOWAIT: "NOWAIT",
SKIP: "SKIP",
LOCKED: "LOCKED",
}

func (tok Token) String() string {
Expand Down
Loading