func (c *ClientConn) handleSetNames(ch, ci sqlparser.ValExpr) error {
var cid mysql.CollationId
var ok bool
value := sqlparser.String(ch)
value = strings.Trim(value, "'`\"")
charset := strings.ToLower(value)
if charset == "null" {
return c.writeOK(nil)
}
if ci == nil {
cid, ok = mysql.CharsetIds[charset]
if !ok {
return fmt.Errorf("invalid charset %s", charset)
}
} else {
collate := sqlparser.String(ci)
collate = strings.Trim(value, "'`\"")
cid, ok = mysql.CollationNames[collate]
if !ok {
return fmt.Errorf("invalid charset %s", charset)
}
}
c.charset = charset
c.collation = cid
return c.writeOK(nil)
}
func (r *Router) buildReplacePlan(statement sqlparser.Statement) (*Plan, error) {
plan := &Plan{}
plan.Rows = make(map[int]sqlparser.Values)
stmt := statement.(*sqlparser.Replace)
if _, ok := stmt.Rows.(sqlparser.SelectStatement); ok {
panic(sqlparser.NewParserError("select in replace not allowed"))
}
if stmt.Columns == nil {
return nil, errors.ErrIRNoColumns
}
plan.Rule = r.GetRule(sqlparser.String(stmt.Table))
err := plan.GetIRKeyIndex(stmt.Columns)
if err != nil {
return nil, err
}
plan.Criteria = plan.checkValuesType(stmt.Rows.(sqlparser.Values))
err = plan.calRouteIndexs()
if err != nil {
golog.Error("Route", "BuildReplacePlan", err.Error(), 0)
return nil, err
}
err = r.generateReplaceSql(plan, stmt)
if err != nil {
return nil, err
}
return plan, nil
}
func (r *Router) buildDeletePlan(statement sqlparser.Statement) (*Plan, error) {
plan := &Plan{}
var where *sqlparser.Where
var err error
stmt := statement.(*sqlparser.Delete)
plan.Rule = r.GetRule(sqlparser.String(stmt.Table))
where = stmt.Where
if where != nil {
plan.Criteria = where.Expr //路由条件
err = plan.calRouteIndexs()
if err != nil {
golog.Error("Route", "BuildUpdatePlan", err.Error(), 0)
return nil, err
}
} else {
//if shard delete without where,send to all nodes and all tables
plan.RouteTableIndexs = plan.Rule.SubTableIndexs
plan.RouteNodeIndexs = makeList(0, len(plan.Rule.Nodes))
}
if plan.Rule.Type != DefaultRuleType && len(plan.RouteTableIndexs) == 0 {
golog.Error("Route", "BuildDeletePlan", errors.ErrNoCriteria.Error(), 0)
return nil, errors.ErrNoCriteria
}
//generate sql,如果routeTableindexs为空则表示不分表，不分表则发default node
err = r.generateDeleteSql(plan, stmt)
if err != nil {
return nil, err
}
return plan, nil
}
func (r *Router) buildSelectPlan(statement sqlparser.Statement) (*Plan, error) {
plan := &Plan{}
var where *sqlparser.Where
var err error
var tableName string
stmt := statement.(*sqlparser.Select)
switch v := (stmt.From[0]).(type) {
case *sqlparser.AliasedTableExpr:
tableName = sqlparser.String(v.Expr)
case *sqlparser.JoinTableExpr:
if ate, ok := (v.LeftExpr).(*sqlparser.AliasedTableExpr); ok {
tableName = sqlparser.String(ate.Expr)
} else {
tableName = sqlparser.String(v)
}
default:
tableName = sqlparser.String(v)
}
plan.Rule = r.GetRule(tableName) //根据表名获得分表规则
where = stmt.Where
if where != nil {
plan.Criteria = where.Expr //路由条件
err = plan.calRouteIndexs()
if err != nil {
golog.Error("Route", "BuildSelectPlan", err.Error(), 0)
return nil, err
}
} else {
//if shard select without where,send to all nodes and all tables
plan.RouteTableIndexs = plan.Rule.SubTableIndexs
plan.RouteNodeIndexs = makeList(0, len(plan.Rule.Nodes))
}
if plan.Rule.Type != DefaultRuleType && len(plan.RouteTableIndexs) == 0 {
golog.Error("Route", "BuildSelectPlan", errors.ErrNoCriteria.Error(), 0)
return nil, errors.ErrNoCriteria
}
//generate sql,如果routeTableindexs为空则表示不分表，不分表则发default node
err = r.generateSelectSql(plan, stmt)
if err != nil {
return nil, err
}
return plan, nil
}
func (r *Router) buildInsertPlan(statement sqlparser.Statement) (*Plan, error) {
plan := &Plan{}
plan.Rows = make(map[int]sqlparser.Values)
stmt := statement.(*sqlparser.Insert)
if _, ok := stmt.Rows.(sqlparser.SelectStatement); ok {
return nil, errors.ErrSelectInInsert
}
if stmt.Columns == nil {
return nil, errors.ErrIRNoColumns
}
//根据sql语句的表，获得对应的分片规则
plan.Rule = r.GetRule(sqlparser.String(stmt.Table))
err := plan.GetIRKeyIndex(stmt.Columns)
if err != nil {
return nil, err
}
if stmt.OnDup != nil {
err := plan.Rule.checkUpdateExprs(sqlparser.UpdateExprs(stmt.OnDup))
if err != nil {
return nil, err
}
}
plan.Criteria = plan.checkValuesType(stmt.Rows.(sqlparser.Values))
err = plan.calRouteIndexs()
if err != nil {
golog.Error("Route", "BuildInsertPlan", err.Error(), 0)
return nil, err
}
err = r.generateInsertSql(plan, stmt)
if err != nil {
return nil, err
}
return plan, nil
}
func (c *ClientConn) handleUseDB(stmt *sqlparser.UseDB) error {
if len(stmt.DB) == 0 {
return fmt.Errorf("must have database, not %s", sqlparser.String(stmt))
}
if c.schema == nil {
return mysql.NewDefaultError(mysql.ER_NO_DB_ERROR)
}
nodeName := c.schema.rule.DefaultRule.Nodes[0]
n := c.proxy.GetNode(nodeName)
co, err := n.GetMasterConn()
defer c.closeConn(co, false)
if err != nil {
return err
}
if err = co.UseDB(string(stmt.DB)); err != nil {
return err
}
c.db = string(stmt.DB)
return c.writeOK(nil)
}
//rewrite select sql
func (r *Router) rewriteSelectSql(plan *Plan, node *sqlparser.Select, tableIndex int) string {
buf := sqlparser.NewTrackedBuffer(nil)
buf.Fprintf("select %v%s%v",
node.Comments,
node.Distinct,
node.SelectExprs,
)
//insert the group columns in the first of select cloumns
if len(node.GroupBy) != 0 {
prefix := ","
for _, n := range node.GroupBy {
buf.Fprintf("%s%v", prefix, n)
}
}
buf.Fprintf(" from ")
switch v := (node.From[0]).(type) {
case *sqlparser.AliasedTableExpr:
if len(v.As) != 0 {
fmt.Fprintf(buf, "%s_%04d as %s",
sqlparser.String(v.Expr),
tableIndex,
string(v.As),
)
} else {
fmt.Fprintf(buf, "%s_%04d",
sqlparser.String(v.Expr),
tableIndex,
)
}
case *sqlparser.JoinTableExpr:
if ate, ok := (v.LeftExpr).(*sqlparser.AliasedTableExpr); ok {
if len(ate.As) != 0 {
fmt.Fprintf(buf, "%s_%04d as %s",
sqlparser.String(ate.Expr),
tableIndex,
string(ate.As),
)
} else {
fmt.Fprintf(buf, "%s_%04d",
sqlparser.String(ate.Expr),
tableIndex,
)
}
} else {
fmt.Fprintf(buf, "%s_%04d",
sqlparser.String(v.LeftExpr),
tableIndex,
)
}
buf.Fprintf(" %s %v", v.Join, v.RightExpr)
if v.On != nil {
buf.Fprintf(" on %v", v.On)
}
default:
fmt.Fprintf(buf, "%s_%04d",
sqlparser.String(node.From[0]),
tableIndex,
)
}
//append other tables
prefix := ", "
for i := 1; i < len(node.From); i++ {
buf.Fprintf("%s%v", prefix, node.From[i])
}
buf.Fprintf("%v%v%v%v%s",
node.Where,
node.GroupBy,
node.Having,
node.OrderBy,
node.Lock,
)
return buf.String()
}