func getMatch(node sqlparser.BoolExpr, index *Index) (planID PlanID, values interface{}) {
switch node := node.(type) {
case *sqlparser.AndExpr:
if planID, values = getMatch(node.Left, index); planID != SelectScatter {
return planID, values
}
if planID, values = getMatch(node.Right, index); planID != SelectScatter {
return planID, values
}
case *sqlparser.ParenBoolExpr:
return getMatch(node.Expr, index)
case *sqlparser.ComparisonExpr:
switch node.Operator {
case "=":
if !nameMatch(node.Left, index.Column) {
return SelectScatter, nil
}
if !sqlparser.IsValue(node.Right) {
return SelectScatter, nil
}
val, err := sqlparser.AsInterface(node.Right)
if err != nil {
return SelectScatter, nil
}
if index.Type == ShardKey {
planID = SelectSingleShardKey
} else {
planID = SelectSingleLookup
}
return planID, val
case "in":
if !nameMatch(node.Left, index.Column) {
return SelectScatter, nil
}
if !sqlparser.IsSimpleTuple(node.Right) {
return SelectScatter, nil
}
val, err := sqlparser.AsInterface(node.Right)
if err != nil {
return SelectScatter, nil
}
node.Right = sqlparser.ListArg("::_vals")
if index.Type == ShardKey {
planID = SelectMultiShardKey
} else {
planID = SelectMultiLookup
}
return planID, val
}
}
return SelectScatter, nil
}
func getMatch(node sqlparser.BoolExpr, col string) (planID PlanID, values interface{}) {
switch node := node.(type) {
case *sqlparser.AndExpr:
if planID, values = getMatch(node.Left, col); planID != SelectScatter {
return planID, values
}
if planID, values = getMatch(node.Right, col); planID != SelectScatter {
return planID, values
}
case *sqlparser.ParenBoolExpr:
return getMatch(node.Expr, col)
case *sqlparser.ComparisonExpr:
switch node.Operator {
case "=":
if !nameMatch(node.Left, col) {
return SelectScatter, nil
}
if !sqlparser.IsValue(node.Right) {
return SelectScatter, nil
}
val, err := asInterface(node.Right)
if err != nil {
return SelectScatter, nil
}
return SelectEqual, val
case "in":
if !nameMatch(node.Left, col) {
return SelectScatter, nil
}
if !sqlparser.IsSimpleTuple(node.Right) {
return SelectScatter, nil
}
val, err := asInterface(node.Right)
if err != nil {
return SelectScatter, nil
}
node.Right = sqlparser.ListArg("::" + ListVarName)
return SelectIN, val
}
}
return SelectScatter, nil
}
// Wireup performs the wire-up tasks.
func (rb *route) Wireup(bldr builder, jt *jointab) error {
// Resolve values stored in the builder.
var err error
switch vals := rb.ERoute.Values.(type) {
case *sqlparser.ComparisonExpr:
// A comparison expression is stored only if it was an IN clause.
// We have to convert it to use a list argutment and resolve values.
rb.ERoute.Values, err = rb.procureValues(bldr, jt, vals.Right)
if err != nil {
return err
}
vals.Right = sqlparser.ListArg("::" + engine.ListVarName)
default:
rb.ERoute.Values, err = rb.procureValues(bldr, jt, vals)
if err != nil {
return err
}
}
// Fix up the AST.
_ = sqlparser.Walk(func(node sqlparser.SQLNode) (bool, error) {
switch node := node.(type) {
case *sqlparser.Select:
if len(node.SelectExprs) == 0 {
node.SelectExprs = sqlparser.SelectExprs([]sqlparser.SelectExpr{
&sqlparser.NonStarExpr{
Expr: sqlparser.NumVal([]byte{'1'}),
},
})
}
case *sqlparser.ComparisonExpr:
if node.Operator == sqlparser.EqualStr {
if exprIsValue(node.Left, rb) && !exprIsValue(node.Right, rb) {
node.Left, node.Right = node.Right, node.Left
}
}
}
return true, nil
}, &rb.Select)
// Generate query while simultaneously resolving values.
varFormatter := func(buf *sqlparser.TrackedBuffer, node sqlparser.SQLNode) {
switch node := node.(type) {
case *sqlparser.ColName:
if !rb.isLocal(node) {
joinVar := jt.Procure(bldr, node, rb.Order())
rb.ERoute.JoinVars[joinVar] = struct{}{}
buf.Myprintf("%a", ":"+joinVar)
return
}
case *sqlparser.TableName:
node.Name.Format(buf)
return
}
node.Format(buf)
}
buf := sqlparser.NewTrackedBuffer(varFormatter)
varFormatter(buf, &rb.Select)
rb.ERoute.Query = buf.ParsedQuery().Query
rb.ERoute.FieldQuery = rb.generateFieldQuery(&rb.Select, jt)
return nil
}