Merge pull request #7164 from planetscale/dual-rewrite

Skip query rewriting for dual table
vitessio · Dec 15, 2020 · 91b10d9 · 91b10d9
2 parents 9592c0f + 1ccc304
commit 91b10d9
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Showing 2 changed files with 11 additions and 3 deletions.
diff --git a/go/vt/sqlparser/ast_rewriting.go b/go/vt/sqlparser/ast_rewriting.go
@@ -169,6 +169,10 @@ func (er *expressionRewriter) rewrite(cursor *Cursor) bool {
  if !ok {
  return true
  }
+ // Qualifier should not be added to dual table
+ if aliasTableName.Name.String() == "dual" {
+ break
+ }
  if er.keyspace != "" && aliasTableName.Qualifier.IsEmpty() {
  aliasTableName.Qualifier = NewTableIdent(er.keyspace)
  node.Expr = aliasTableName

diff --git a/go/vt/sqlparser/ast_rewriting_test.go b/go/vt/sqlparser/ast_rewriting_test.go
@@ -225,6 +225,12 @@ func TestRewritesWithDefaultKeyspace(in *testing.T) {
  }, {
  in: "SELECT 1 from test where exists (select 2 from test)",
  expected: "SELECT 1 from sys.test where exists (select 2 from sys.test)",
+ }, {
+ in: "SELECT 1 from dual",
+ expected: "SELECT 1 from dual",
+ }, {
+ in: "SELECT (select 2 from dual) from DUAL",
+ expected: "SELECT 2 as `(select 2 from dual)` from DUAL",
  }}
 
  for _, tc := range tests {
@@ -239,9 +245,7 @@ func TestRewritesWithDefaultKeyspace(in *testing.T) {
  expected, err := Parse(tc.expected)
  require.NoError(err, "test expectation does not parse [%s]", tc.expected)
 
- s := String(expected)
- assert := assert.New(t)
- assert.Equal(s, String(result.AST))
+ assert.Equal(t, String(expected), String(result.AST))
  })
  }
 }