// Find returns the route for the symbol referenced by col.
// If a reference is found, the column's Metadata is set to point
// it. Subsequent searches will reuse this meatadata.
// If autoResolve is true, and there is only one table in the symbol table,
// then an unqualified reference is assumed to be implicitly against
// that table. The table info doesn't contain the full list of columns.
// So, any column reference is presumed valid. If a Colsyms scope is
// present, then the table scope is not searched. If a symbol is found
// in the current symtab, then isLocal is set to true. Otherwise, the
// search is continued in the outer symtab. If so, isLocal will be set
// to false. If the symbol was not found, an error is returned.
// isLocal must be checked before you can push-down (or pull-out)
// a construct.
// If a symbol was found in an outer scope, then the column reference
// is added to the Externs field.
func (st *symtab) Find(col *sqlparser.ColName, autoResolve bool) (rb *route, isLocal bool, err error) {
if m, ok := col.Metadata.(sym); ok {
return m.Route(), m.Symtab() == st, nil
}
if len(st.Colsyms) != 0 {
name := sqlparser.SQLName(sqlparser.String(col))
starname := sqlparser.SQLName(sqlparser.String(&sqlparser.ColName{
Name: "*",
Qualifier: col.Qualifier,
}))
for _, colsym := range st.Colsyms {
if name == colsym.Alias || starname == colsym.Alias || colsym.Alias == "*" {
col.Metadata = colsym
return colsym.Route(), true, nil
}
}
if st.Outer != nil {
// autoResolve only allowed for innermost scope.
rb, _, err = st.Outer.Find(col, false)
if err == nil {
st.Externs = append(st.Externs, col)
}
return rb, false, err
}
return nil, false, fmt.Errorf("symbol %s not found", sqlparser.String(col))
}
qualifier := sqlparser.SQLName(sqlparser.String(col.Qualifier))
if qualifier == "" && autoResolve && len(st.tables) == 1 {
for _, t := range st.tables {
qualifier = t.Alias
break
}
}
alias := st.findTable(qualifier)
if alias == nil {
if st.Outer != nil {
// autoResolve only allowed for innermost scope.
rb, _, err = st.Outer.Find(col, false)
if err == nil {
st.Externs = append(st.Externs, col)
}
return rb, false, err
}
return nil, false, fmt.Errorf("symbol %s not found", sqlparser.String(col))
}
col.Metadata = alias
return alias.Route(), true, nil
}
// PushStar pushes the '*' expression into the route.
func (rb *route) PushStar(expr *sqlparser.StarExpr) *colsym {
colsym := newColsym(rb, rb.Symtab())
colsym.Alias = sqlparser.SQLName(sqlparser.String(expr))
rb.Select.SelectExprs = append(rb.Select.SelectExprs, expr)
rb.Colsyms = append(rb.Colsyms, colsym)
return colsym
}
func convertColumnNamesToValExpr(colNames []string) []sqlparser.ValExpr {
valExprs := make([]sqlparser.ValExpr, 0, len(colNames))
for _, colName := range colNames {
valExprs = append(valExprs, &sqlparser.ColName{Name: sqlparser.SQLName(colName)})
}
return valExprs
}
// processAliasedTable produces a builder subtree for the given AliasedTableExpr.
// If the expression is a subquery, then the the route built for it will contain
// the entire subquery tree in the from clause, as if it was a table.
// The symtab entry for the query will be a tabsym where the columns
// will be built from the select expressions of the subquery.
// Since the table aliases only contain vindex columns, we'll follow
// the same rule: only columns from the subquery that are identified as
// vindex columns will be added to the tabsym.
// A symtab symbol can only point to a route. This means that we canoot
// support complex joins in subqueries yet.
func processAliasedTable(tableExpr *sqlparser.AliasedTableExpr, vschema VSchema) (builder, error) {
switch expr := tableExpr.Expr.(type) {
case *sqlparser.TableName:
eroute, table, err := getTablePlan(expr, vschema)
if err != nil {
return nil, err
}
alias := sqlparser.SQLName(sqlparser.String(expr))
astName := expr.Name
if tableExpr.As != "" {
alias = tableExpr.As
astName = alias
}
return newRoute(
sqlparser.TableExprs([]sqlparser.TableExpr{tableExpr}),
eroute,
table,
vschema,
alias,
astName,
), nil
case *sqlparser.Subquery:
sel, ok := expr.Select.(*sqlparser.Select)
if !ok {
return nil, errors.New("unsupported: union operator in subqueries")
}
subplan, err := processSelect(sel, vschema, nil)
if err != nil {
return nil, err
}
subroute, ok := subplan.(*route)
if !ok {
return nil, errors.New("unsupported: complex join in subqueries")
}
table := &vindexes.Table{
Keyspace: subroute.ERoute.Keyspace,
}
for _, colsyms := range subroute.Colsyms {
if colsyms.Vindex == nil {
continue
}
table.ColVindexes = append(table.ColVindexes, &vindexes.ColVindex{
Col: string(colsyms.Alias),
Vindex: colsyms.Vindex,
})
}
rtb := newRoute(
sqlparser.TableExprs([]sqlparser.TableExpr{tableExpr}),
subroute.ERoute,
table,
vschema,
tableExpr.As,
tableExpr.As,
)
subroute.Redirect = rtb
return rtb, nil
}
panic("unreachable")
}
func buildOrderByClause(splitColumns []string) sqlparser.OrderBy {
result := make(sqlparser.OrderBy, 0, len(splitColumns))
for _, splitColumn := range splitColumns {
result = append(result,
&sqlparser.Order{
Expr: &sqlparser.ColName{Name: sqlparser.SQLName(splitColumn)},
Direction: sqlparser.AscScr,
},
)
}
return result
}
func convertColumnNamesToSelectExprs(columnNames []string) sqlparser.SelectExprs {
result := make([]sqlparser.SelectExpr, 0, len(columnNames))
for _, columnName := range columnNames {
result = append(result,
&sqlparser.NonStarExpr{
Expr: &sqlparser.ColName{
Name: sqlparser.SQLName(columnName),
},
})
}
return result
}
// getWhereClause returns a whereClause based on desired upper and lower
// bounds for primary key.
func (qs *QuerySplitter) getWhereClause(whereClause *sqlparser.Where, bindVars map[string]interface{}, start, end sqltypes.Value) *sqlparser.Where {
var startClause *sqlparser.ComparisonExpr
var endClause *sqlparser.ComparisonExpr
var clauses sqlparser.BoolExpr
// No upper or lower bound, just return the where clause of original query
if start.IsNull() && end.IsNull() {
return whereClause
}
pk := &sqlparser.ColName{
Name: sqlparser.SQLName(qs.splitColumn),
}
if !start.IsNull() {
startClause = &sqlparser.ComparisonExpr{
Operator: sqlparser.GreaterEqualStr,
Left: pk,
Right: sqlparser.ValArg([]byte(":" + startBindVarName)),
}
bindVars[startBindVarName] = start.ToNative()
}
// splitColumn < end
if !end.IsNull() {
endClause = &sqlparser.ComparisonExpr{
Operator: sqlparser.LessThanStr,
Left: pk,
Right: sqlparser.ValArg([]byte(":" + endBindVarName)),
}
bindVars[endBindVarName] = end.ToNative()
}
if startClause == nil {
clauses = endClause
} else {
if endClause == nil {
clauses = startClause
} else {
// splitColumn >= start AND splitColumn < end
clauses = &sqlparser.AndExpr{
Left: startClause,
Right: endClause,
}
}
}
if whereClause != nil {
clauses = &sqlparser.AndExpr{
Left: &sqlparser.ParenBoolExpr{Expr: whereClause.Expr},
Right: &sqlparser.ParenBoolExpr{Expr: clauses},
}
}
return &sqlparser.Where{
Type: sqlparser.WhereStr,
Expr: clauses,
}
}
// getWhereClause returns a whereClause based on desired upper and lower
// bounds for primary key.
func (qs *QuerySplitter) getWhereClause(start, end sqltypes.Value) *sqlparser.Where {
var startClause *sqlparser.ComparisonExpr
var endClause *sqlparser.ComparisonExpr
var clauses sqlparser.BoolExpr
// No upper or lower bound, just return the where clause of original query
if start.IsNull() && end.IsNull() {
return qs.sel.Where
}
pk := &sqlparser.ColName{
Name: sqlparser.SQLName(qs.splitColumn),
}
// splitColumn >= start
if !start.IsNull() {
startClause = &sqlparser.ComparisonExpr{
Operator: sqlparser.AST_GE,
Left: pk,
Right: sqlparser.NumVal((start).Raw()),
}
}
// splitColumn < end
if !end.IsNull() {
endClause = &sqlparser.ComparisonExpr{
Operator: sqlparser.AST_LT,
Left: pk,
Right: sqlparser.NumVal((end).Raw()),
}
}
if startClause == nil {
clauses = endClause
} else {
if endClause == nil {
clauses = startClause
} else {
// splitColumn >= start AND splitColumn < end
clauses = &sqlparser.AndExpr{
Left: startClause,
Right: endClause,
}
}
}
if qs.sel.Where != nil {
clauses = &sqlparser.AndExpr{
Left: qs.sel.Where.Expr,
Right: clauses,
}
}
return &sqlparser.Where{
Type: sqlparser.AST_WHERE,
Expr: clauses,
}
}
// GenerateSelectSubquery generates the subquery for selects.
func GenerateSelectSubquery(sel *sqlparser.Select, tableInfo *schema.Table, index string) *sqlparser.ParsedQuery {
hint := &sqlparser.IndexHints{Type: sqlparser.UseStr, Indexes: []sqlparser.SQLName{sqlparser.SQLName(index)}}
tableExpr := sel.From[0].(*sqlparser.AliasedTableExpr)
savedHint := tableExpr.Hints
tableExpr.Hints = hint
defer func() {
tableExpr.Hints = savedHint
}()
return GenerateSubquery(
tableInfo.Indexes[0].Columns,
tableExpr,
sel.Where,
sel.OrderBy,
sel.Limit,
false,
)
}
// PushSelect pushes the select expression into the route.
func (rb *route) PushSelect(expr *sqlparser.NonStarExpr, _ *route) (colsym *colsym, colnum int, err error) {
colsym = newColsym(rb, rb.Symtab())
if expr.As != "" {
colsym.Alias = expr.As
}
if col, ok := expr.Expr.(*sqlparser.ColName); ok {
if colsym.Alias == "" {
colsym.Alias = sqlparser.SQLName(sqlparser.String(col))
}
colsym.Vindex = rb.Symtab().Vindex(col, rb, true)
colsym.Underlying = newColref(col)
} else {
if rb.IsRHS {
return nil, 0, errors.New("unsupported: complex left join and column expressions")
}
}
rb.Select.SelectExprs = append(rb.Select.SelectExprs, expr)
rb.Colsyms = append(rb.Colsyms, colsym)
return colsym, len(rb.Colsyms) - 1, nil
}
func buildIndexPlan(ins *sqlparser.Insert, tablename string, colVindex *ColVindex, plan *Plan) error {
pos := -1
for i, column := range ins.Columns {
if colVindex.Col == sqlparser.GetColName(column.(*sqlparser.NonStarExpr).Expr) {
pos = i
break
}
}
if pos == -1 {
pos = len(ins.Columns)
ins.Columns = append(ins.Columns, &sqlparser.NonStarExpr{Expr: &sqlparser.ColName{Name: sqlparser.SQLName(colVindex.Col)}})
ins.Rows.(sqlparser.Values)[0] = append(ins.Rows.(sqlparser.Values)[0].(sqlparser.ValTuple), &sqlparser.NullVal{})
}
row := ins.Rows.(sqlparser.Values)[0].(sqlparser.ValTuple)
val, err := asInterface(row[pos])
if err != nil {
return fmt.Errorf("could not convert val: %s, pos: %d: %v", sqlparser.String(row[pos]), pos, err)
}
plan.Values = append(plan.Values.([]interface{}), val)
row[pos] = sqlparser.ValArg([]byte(fmt.Sprintf(":_%s", colVindex.Col)))
return nil
}
func findOrInsertPos(ins *sqlparser.Insert, col string) (row sqlparser.ValTuple, pos int) {
pos = -1
for i, column := range ins.Columns {
if col == sqlparser.GetColName(column.(*sqlparser.NonStarExpr).Expr) {
pos = i
break
}
}
if pos == -1 {
pos = len(ins.Columns)
ins.Columns = append(ins.Columns, &sqlparser.NonStarExpr{Expr: &sqlparser.ColName{Name: sqlparser.SQLName(col)}})
ins.Rows.(sqlparser.Values)[0] = append(ins.Rows.(sqlparser.Values)[0].(sqlparser.ValTuple), &sqlparser.NullVal{})
}
return ins.Rows.(sqlparser.Values)[0].(sqlparser.ValTuple), pos
}
// getWhereClause returns a whereClause based on desired upper and lower
// bounds for primary key.
func (qs *QuerySplitter) getWhereClause(whereClause *sqlparser.Where, bindVars map[string]interface{}, start, end sqltypes.Value) *sqlparser.Where {
var startClause *sqlparser.ComparisonExpr
var endClause *sqlparser.ComparisonExpr
var clauses sqlparser.BoolExpr
// No upper or lower bound, just return the where clause of original query
if start.IsNull() && end.IsNull() {
return whereClause
}
pk := &sqlparser.ColName{
Name: sqlparser.SQLName(qs.splitColumn),
}
if !start.IsNull() {
startClause = &sqlparser.ComparisonExpr{
Operator: sqlparser.AST_GE,
Left: pk,
Right: sqlparser.ValArg([]byte(":" + startBindVarName)),
}
if start.IsNumeric() {
v, _ := start.ParseInt64()
bindVars[startBindVarName] = v
} else if start.IsString() {
bindVars[startBindVarName] = start.Raw()
} else if start.IsFractional() {
v, _ := start.ParseFloat64()
bindVars[startBindVarName] = v
}
}
// splitColumn < end
if !end.IsNull() {
endClause = &sqlparser.ComparisonExpr{
Operator: sqlparser.AST_LT,
Left: pk,
Right: sqlparser.ValArg([]byte(":" + endBindVarName)),
}
if end.IsNumeric() {
v, _ := end.ParseInt64()
bindVars[endBindVarName] = v
} else if end.IsString() {
bindVars[endBindVarName] = end.Raw()
} else if end.IsFractional() {
v, _ := end.ParseFloat64()
bindVars[endBindVarName] = v
}
}
if startClause == nil {
clauses = endClause
} else {
if endClause == nil {
clauses = startClause
} else {
// splitColumn >= start AND splitColumn < end
clauses = &sqlparser.AndExpr{
Left: startClause,
Right: endClause,
}
}
}
if whereClause != nil {
clauses = &sqlparser.AndExpr{
Left: &sqlparser.ParenBoolExpr{Expr: whereClause.Expr},
Right: &sqlparser.ParenBoolExpr{Expr: clauses},
}
}
return &sqlparser.Where{
Type: sqlparser.AST_WHERE,
Expr: clauses,
}
}