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[release-17.0] Make column resolution closer to MySQL (#14426) (#14429)
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Signed-off-by: Andres Taylor <andres@planetscale.com>
Co-authored-by: Andres Taylor <andres@planetscale.com>
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@vitess-bot @systay
vitess-bot[bot] and systay authored Nov 10, 2023
1 parent 7800fe5 commit 15214fc
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Showing 3 changed files with 112 additions and 15 deletions.
38 changes: 28 additions & 10 deletions go/vt/vtgate/planbuilder/operators/queryprojection.go
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Original file line number Diff line number Diff line change
Expand Up @@ -460,29 +460,47 @@ func (qp *QueryProjection) isExprInGroupByExprs(ctx *plancontext.PlanningContext
}

// GetSimplifiedExpr takes an expression used in ORDER BY or GROUP BY, and returns an expression that is simpler to evaluate
func (qp *QueryProjection) GetSimplifiedExpr(e sqlparser.Expr) sqlparser.Expr {
func (qp *QueryProjection) GetSimplifiedExpr(e sqlparser.Expr) (found sqlparser.Expr) {
if qp == nil {
return e
}
// If the ORDER BY is against a column alias, we need to remember the expression
// behind the alias. The weightstring(.) calls needs to be done against that expression and not the alias.
// Eg - select music.foo as bar, weightstring(music.foo) from music order by bar

colExpr, isColName := e.(*sqlparser.ColName)
if !(isColName && colExpr.Qualifier.IsEmpty()) {
// we are only interested in unqualified column names. if it's not a column name and not
in, isColName := e.(*sqlparser.ColName)
if !(isColName && in.Qualifier.IsEmpty()) {
// we are only interested in unqualified column names. if it's not a column name and not unqualified, we're done
return e
}

for _, selectExpr := range qp.SelectExprs {
aliasedExpr, isAliasedExpr := selectExpr.Col.(*sqlparser.AliasedExpr)
if !isAliasedExpr {
ae, ok := selectExpr.Col.(*sqlparser.AliasedExpr)
if !ok {
continue
}
aliased := !aliasedExpr.As.IsEmpty()
if aliased && colExpr.Name.Equal(aliasedExpr.As) {
return aliasedExpr.Expr
aliased := !ae.As.IsEmpty()
if aliased {
if in.Name.Equal(ae.As) {
return ae.Expr
}
} else {
seCol, ok := ae.Expr.(*sqlparser.ColName)
if !ok {
continue
}
if seCol.Name.Equal(in.Name) {
// If the column name matches, we have a match, even if the table name is not listed
return ae.Expr
}
}
}

return e
if found == nil {
found = e
}

return found
}

// toString should only be used for tests
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10 changes: 5 additions & 5 deletions go/vt/vtgate/planbuilder/testdata/aggr_cases.json
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Original file line number Diff line number Diff line change
Expand Up @@ -4592,7 +4592,7 @@
"Instructions": {
"OperatorType": "Sort",
"Variant": "Memory",
"OrderBy": "(1|3) ASC",
"OrderBy": "(0|3) ASC",
"ResultColumns": 3,
"Inputs": [
{
Expand All @@ -4607,8 +4607,8 @@
"Name": "user",
"Sharded": true
},
"FieldQuery": "select id, b as id, count(*), weight_string(b) from `user` where 1 != 1",
"Query": "select id, b as id, count(*), weight_string(b) from `user`",
"FieldQuery": "select id, b as id, count(*), weight_string(id) from `user` where 1 != 1",
"Query": "select id, b as id, count(*), weight_string(id) from `user`",
"Table": "`user`"
}
]
Expand Down Expand Up @@ -4697,9 +4697,9 @@
"Name": "user",
"Sharded": true
},
"FieldQuery": "select `user`.id, weight_string(id) from `user` where 1 != 1 group by id, weight_string(id)",
"FieldQuery": "select `user`.id, weight_string(`user`.id) from `user` where 1 != 1 group by id, weight_string(`user`.id)",
"OrderBy": "(0|1) ASC",
"Query": "select `user`.id, weight_string(id) from `user` group by id, weight_string(id) order by id asc",
"Query": "select `user`.id, weight_string(`user`.id) from `user` group by id, weight_string(`user`.id) order by id asc",
"Table": "`user`"
},
{
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79 changes: 79 additions & 0 deletions go/vt/vtgate/planbuilder/testdata/select_cases.json
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Original file line number Diff line number Diff line change
Expand Up @@ -8411,5 +8411,84 @@
"user.customer"
]
}
},
{
"comment": "column with qualifier is correctly used",
"query": "select u.foo, ue.foo as apa from user u, user_extra ue order by foo ",
"v3-plan": {
"QueryType": "SELECT",
"Original": "select u.foo, ue.foo as apa from user u, user_extra ue order by foo ",
"Instructions": {
"OperatorType": "Join",
"Variant": "Join",
"JoinColumnIndexes": "L:0,R:0",
"TableName": "`user`_user_extra",
"Inputs": [
{
"OperatorType": "Route",
"Variant": "Scatter",
"Keyspace": {
"Name": "user",
"Sharded": true
},
"FieldQuery": "select u.foo, weight_string(u.foo) from `user` as u where 1 != 1",
"OrderBy": "(0|1) ASC",
"Query": "select u.foo, weight_string(u.foo) from `user` as u order by foo asc",
"ResultColumns": 1,
"Table": "`user`"
},
{
"OperatorType": "Route",
"Variant": "Scatter",
"Keyspace": {
"Name": "user",
"Sharded": true
},
"FieldQuery": "select ue.foo as apa from user_extra as ue where 1 != 1",
"Query": "select ue.foo as apa from user_extra as ue",
"Table": "user_extra"
}
]
}
},
"gen4-plan": {
"QueryType": "SELECT",
"Original": "select u.foo, ue.foo as apa from user u, user_extra ue order by foo ",
"Instructions": {
"OperatorType": "Join",
"Variant": "Join",
"JoinColumnIndexes": "L:0,R:0",
"TableName": "`user`_user_extra",
"Inputs": [
{
"OperatorType": "Route",
"Variant": "Scatter",
"Keyspace": {
"Name": "user",
"Sharded": true
},
"FieldQuery": "select u.foo, weight_string(u.foo) from `user` as u where 1 != 1",
"OrderBy": "(0|1) ASC",
"Query": "select u.foo, weight_string(u.foo) from `user` as u order by foo asc",
"Table": "`user`"
},
{
"OperatorType": "Route",
"Variant": "Scatter",
"Keyspace": {
"Name": "user",
"Sharded": true
},
"FieldQuery": "select ue.foo as apa from user_extra as ue where 1 != 1",
"Query": "select ue.foo as apa from user_extra as ue",
"Table": "user_extra"
}
]
},
"TablesUsed": [
"user.user",
"user.user_extra"
]
}
}
]

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