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minio/pkg/s3select/sql/sql.go

529 lines
14 KiB

/*
* Minio Cloud Storage, (C) 2019 Minio, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package sql
import (
"fmt"
"strings"
"github.com/xwb1989/sqlparser"
)
func getColumnName(colName *sqlparser.ColName) string {
columnName := colName.Qualifier.Name.String()
if qualifier := colName.Qualifier.Qualifier.String(); qualifier != "" {
columnName = qualifier + "." + columnName
}
if columnName == "" {
columnName = colName.Name.String()
} else {
columnName = columnName + "." + colName.Name.String()
}
return columnName
}
func newLiteralExpr(parserExpr sqlparser.Expr, tableAlias string) (Expr, error) {
switch parserExpr.(type) {
case *sqlparser.NullVal:
return newValueExpr(NewNull()), nil
case sqlparser.BoolVal:
return newValueExpr(NewBool((bool(parserExpr.(sqlparser.BoolVal))))), nil
case *sqlparser.SQLVal:
sqlValue := parserExpr.(*sqlparser.SQLVal)
value, err := NewValue(sqlValue)
if err != nil {
return nil, err
}
return newValueExpr(value), nil
case *sqlparser.ColName:
columnName := getColumnName(parserExpr.(*sqlparser.ColName))
if tableAlias != "" {
if !strings.HasPrefix(columnName, tableAlias+".") {
err := fmt.Errorf("column name %v does not start with table alias %v", columnName, tableAlias)
return nil, errInvalidKeyPath(err)
}
columnName = strings.TrimPrefix(columnName, tableAlias+".")
}
return newColumnExpr(columnName), nil
case sqlparser.ValTuple:
var valueType Type
var values []*Value
for i, valExpr := range parserExpr.(sqlparser.ValTuple) {
sqlVal, ok := valExpr.(*sqlparser.SQLVal)
if !ok {
return nil, errParseInvalidTypeParam(fmt.Errorf("value %v in Tuple should be primitive value", i+1))
}
val, err := NewValue(sqlVal)
if err != nil {
return nil, err
}
if i == 0 {
valueType = val.Type()
} else if valueType != val.Type() {
return nil, errParseInvalidTypeParam(fmt.Errorf("mixed value type is not allowed in Tuple"))
}
values = append(values, val)
}
return newValueExpr(NewArray(values)), nil
}
return nil, nil
}
func isExprToComparisonExpr(parserExpr *sqlparser.IsExpr, tableAlias string, isSelectExpr bool) (Expr, error) {
leftExpr, err := newExpr(parserExpr.Expr, tableAlias, isSelectExpr)
if err != nil {
return nil, err
}
f, err := newComparisonExpr(ComparisonOperator(parserExpr.Operator), leftExpr)
if err != nil {
return nil, err
}
if !leftExpr.Type().isBase() {
return f, nil
}
value, err := f.Eval(nil)
if err != nil {
return nil, err
}
return newValueExpr(value), nil
}
func rangeCondToComparisonFunc(parserExpr *sqlparser.RangeCond, tableAlias string, isSelectExpr bool) (Expr, error) {
leftExpr, err := newExpr(parserExpr.Left, tableAlias, isSelectExpr)
if err != nil {
return nil, err
}
fromExpr, err := newExpr(parserExpr.From, tableAlias, isSelectExpr)
if err != nil {
return nil, err
}
toExpr, err := newExpr(parserExpr.To, tableAlias, isSelectExpr)
if err != nil {
return nil, err
}
f, err := newComparisonExpr(ComparisonOperator(parserExpr.Operator), leftExpr, fromExpr, toExpr)
if err != nil {
return nil, err
}
if !leftExpr.Type().isBase() || !fromExpr.Type().isBase() || !toExpr.Type().isBase() {
return f, nil
}
value, err := f.Eval(nil)
if err != nil {
return nil, err
}
return newValueExpr(value), nil
}
func toComparisonExpr(parserExpr *sqlparser.ComparisonExpr, tableAlias string, isSelectExpr bool) (Expr, error) {
leftExpr, err := newExpr(parserExpr.Left, tableAlias, isSelectExpr)
if err != nil {
return nil, err
}
rightExpr, err := newExpr(parserExpr.Right, tableAlias, isSelectExpr)
if err != nil {
return nil, err
}
f, err := newComparisonExpr(ComparisonOperator(parserExpr.Operator), leftExpr, rightExpr)
if err != nil {
return nil, err
}
if !leftExpr.Type().isBase() || !rightExpr.Type().isBase() {
return f, nil
}
value, err := f.Eval(nil)
if err != nil {
return nil, err
}
return newValueExpr(value), nil
}
func toArithExpr(parserExpr *sqlparser.BinaryExpr, tableAlias string, isSelectExpr bool) (Expr, error) {
leftExpr, err := newExpr(parserExpr.Left, tableAlias, isSelectExpr)
if err != nil {
return nil, err
}
rightExpr, err := newExpr(parserExpr.Right, tableAlias, isSelectExpr)
if err != nil {
return nil, err
}
f, err := newArithExpr(ArithOperator(parserExpr.Operator), leftExpr, rightExpr)
if err != nil {
return nil, err
}
if !leftExpr.Type().isBase() || !rightExpr.Type().isBase() {
return f, nil
}
value, err := f.Eval(nil)
if err != nil {
return nil, err
}
return newValueExpr(value), nil
}
func toFuncExpr(parserExpr *sqlparser.FuncExpr, tableAlias string, isSelectExpr bool) (Expr, error) {
funcName := strings.ToUpper(parserExpr.Name.String())
if !isSelectExpr && isAggregateFuncName(funcName) {
return nil, errUnsupportedSQLOperation(fmt.Errorf("%v() must be used in select expression", funcName))
}
funcs, aggregatedExprFound, err := newSelectExprs(parserExpr.Exprs, tableAlias)
if err != nil {
return nil, err
}
if aggregatedExprFound {
return nil, errIncorrectSQLFunctionArgumentType(fmt.Errorf("%v(): aggregated expression must not be used as argument", funcName))
}
return newFuncExpr(FuncName(funcName), funcs...)
}
func toAndExpr(parserExpr *sqlparser.AndExpr, tableAlias string, isSelectExpr bool) (Expr, error) {
leftExpr, err := newExpr(parserExpr.Left, tableAlias, isSelectExpr)
if err != nil {
return nil, err
}
rightExpr, err := newExpr(parserExpr.Right, tableAlias, isSelectExpr)
if err != nil {
return nil, err
}
f, err := newAndExpr(leftExpr, rightExpr)
if err != nil {
return nil, err
}
if leftExpr.Type() != Bool || rightExpr.Type() != Bool {
return f, nil
}
value, err := f.Eval(nil)
if err != nil {
return nil, err
}
return newValueExpr(value), nil
}
func toOrExpr(parserExpr *sqlparser.OrExpr, tableAlias string, isSelectExpr bool) (Expr, error) {
leftExpr, err := newExpr(parserExpr.Left, tableAlias, isSelectExpr)
if err != nil {
return nil, err
}
rightExpr, err := newExpr(parserExpr.Right, tableAlias, isSelectExpr)
if err != nil {
return nil, err
}
f, err := newOrExpr(leftExpr, rightExpr)
if err != nil {
return nil, err
}
if leftExpr.Type() != Bool || rightExpr.Type() != Bool {
return f, nil
}
value, err := f.Eval(nil)
if err != nil {
return nil, err
}
return newValueExpr(value), nil
}
func toNotExpr(parserExpr *sqlparser.NotExpr, tableAlias string, isSelectExpr bool) (Expr, error) {
rightExpr, err := newExpr(parserExpr.Expr, tableAlias, isSelectExpr)
if err != nil {
return nil, err
}
f, err := newNotExpr(rightExpr)
if err != nil {
return nil, err
}
if rightExpr.Type() != Bool {
return f, nil
}
value, err := f.Eval(nil)
if err != nil {
return nil, err
}
return newValueExpr(value), nil
}
func newExpr(parserExpr sqlparser.Expr, tableAlias string, isSelectExpr bool) (Expr, error) {
f, err := newLiteralExpr(parserExpr, tableAlias)
if err != nil {
return nil, err
}
if f != nil {
return f, nil
}
switch parserExpr.(type) {
case *sqlparser.ParenExpr:
return newExpr(parserExpr.(*sqlparser.ParenExpr).Expr, tableAlias, isSelectExpr)
case *sqlparser.IsExpr:
return isExprToComparisonExpr(parserExpr.(*sqlparser.IsExpr), tableAlias, isSelectExpr)
case *sqlparser.RangeCond:
return rangeCondToComparisonFunc(parserExpr.(*sqlparser.RangeCond), tableAlias, isSelectExpr)
case *sqlparser.ComparisonExpr:
return toComparisonExpr(parserExpr.(*sqlparser.ComparisonExpr), tableAlias, isSelectExpr)
case *sqlparser.BinaryExpr:
return toArithExpr(parserExpr.(*sqlparser.BinaryExpr), tableAlias, isSelectExpr)
case *sqlparser.FuncExpr:
return toFuncExpr(parserExpr.(*sqlparser.FuncExpr), tableAlias, isSelectExpr)
case *sqlparser.AndExpr:
return toAndExpr(parserExpr.(*sqlparser.AndExpr), tableAlias, isSelectExpr)
case *sqlparser.OrExpr:
return toOrExpr(parserExpr.(*sqlparser.OrExpr), tableAlias, isSelectExpr)
case *sqlparser.NotExpr:
return toNotExpr(parserExpr.(*sqlparser.NotExpr), tableAlias, isSelectExpr)
}
return nil, errParseUnsupportedSyntax(fmt.Errorf("unknown expression type %T; %v", parserExpr, parserExpr))
}
func newSelectExprs(parserSelectExprs []sqlparser.SelectExpr, tableAlias string) ([]Expr, bool, error) {
var funcs []Expr
starExprFound := false
aggregatedExprFound := false
for _, selectExpr := range parserSelectExprs {
switch selectExpr.(type) {
case *sqlparser.AliasedExpr:
if starExprFound {
return nil, false, errParseAsteriskIsNotAloneInSelectList(nil)
}
aliasedExpr := selectExpr.(*sqlparser.AliasedExpr)
f, err := newExpr(aliasedExpr.Expr, tableAlias, true)
if err != nil {
return nil, false, err
}
if f.Type() == aggregateFunction {
if !aggregatedExprFound {
aggregatedExprFound = true
if len(funcs) > 0 {
return nil, false, errParseUnsupportedSyntax(fmt.Errorf("expression must not mixed with aggregated expression"))
}
}
} else if aggregatedExprFound {
return nil, false, errParseUnsupportedSyntax(fmt.Errorf("expression must not mixed with aggregated expression"))
}
alias := aliasedExpr.As.String()
if alias != "" {
f = newAliasExpr(alias, f)
}
funcs = append(funcs, f)
case *sqlparser.StarExpr:
if starExprFound {
err := fmt.Errorf("only single star expression allowed")
return nil, false, errParseInvalidContextForWildcardInSelectList(err)
}
starExprFound = true
funcs = append(funcs, newStarExpr())
default:
return nil, false, errParseUnsupportedSyntax(fmt.Errorf("unknown select expression %v", selectExpr))
}
}
return funcs, aggregatedExprFound, nil
}
// Select - SQL Select statement.
type Select struct {
tableName string
tableAlias string
selectExprs []Expr
aggregatedExprFound bool
whereExpr Expr
}
// TableAlias - returns table alias name.
func (statement *Select) TableAlias() string {
return statement.tableAlias
}
// IsSelectAll - returns whether '*' is used in select expression or not.
func (statement *Select) IsSelectAll() bool {
if len(statement.selectExprs) == 1 {
_, ok := statement.selectExprs[0].(*starExpr)
return ok
}
return false
}
// IsAggregated - returns whether aggregated functions are used in select expression or not.
func (statement *Select) IsAggregated() bool {
return statement.aggregatedExprFound
}
// AggregateResult - returns aggregate result as record.
func (statement *Select) AggregateResult(output Record) error {
if !statement.aggregatedExprFound {
return nil
}
for i, expr := range statement.selectExprs {
value, err := expr.AggregateValue()
if err != nil {
return err
}
if value == nil {
return errInternalError(fmt.Errorf("%v returns <nil> for AggregateValue()", expr))
}
name := fmt.Sprintf("_%v", i+1)
if _, ok := expr.(*aliasExpr); ok {
name = expr.(*aliasExpr).alias
}
if err = output.Set(name, value); err != nil {
return errInternalError(fmt.Errorf("error occurred to store value %v for %v; %v", value, name, err))
}
}
return nil
}
// Eval - evaluates this Select expressions for given record.
func (statement *Select) Eval(input, output Record) (Record, error) {
if statement.whereExpr != nil {
value, err := statement.whereExpr.Eval(input)
if err != nil {
return nil, err
}
if value == nil || value.valueType != Bool {
err = fmt.Errorf("WHERE expression %v returns invalid bool value %v", statement.whereExpr, value)
return nil, errInternalError(err)
}
if !value.BoolValue() {
return nil, nil
}
}
// Call selectExprs
for i, expr := range statement.selectExprs {
value, err := expr.Eval(input)
if err != nil {
return nil, err
}
if statement.aggregatedExprFound {
continue
}
name := fmt.Sprintf("_%v", i+1)
switch expr.(type) {
case *starExpr:
return value.recordValue(), nil
case *aliasExpr:
name = expr.(*aliasExpr).alias
case *columnExpr:
name = expr.(*columnExpr).name
}
if err = output.Set(name, value); err != nil {
return nil, errInternalError(fmt.Errorf("error occurred to store value %v for %v; %v", value, name, err))
}
}
return output, nil
}
// NewSelect - creates new Select by parsing sql.
func NewSelect(sql string) (*Select, error) {
stmt, err := sqlparser.Parse(sql)
if err != nil {
return nil, errUnsupportedSQLStructure(err)
}
selectStmt, ok := stmt.(*sqlparser.Select)
if !ok {
return nil, errParseUnsupportedSelect(fmt.Errorf("unsupported SQL statement %v", sql))
}
var tableName, tableAlias string
for _, fromExpr := range selectStmt.From {
tableExpr := fromExpr.(*sqlparser.AliasedTableExpr)
tableName = tableExpr.Expr.(sqlparser.TableName).Name.String()
tableAlias = tableExpr.As.String()
}
selectExprs, aggregatedExprFound, err := newSelectExprs(selectStmt.SelectExprs, tableAlias)
if err != nil {
return nil, err
}
var whereExpr Expr
if selectStmt.Where != nil {
whereExpr, err = newExpr(selectStmt.Where.Expr, tableAlias, false)
if err != nil {
return nil, err
}
}
return &Select{
tableName: tableName,
tableAlias: tableAlias,
selectExprs: selectExprs,
aggregatedExprFound: aggregatedExprFound,
whereExpr: whereExpr,
}, nil
}