func (c *ClientConn) handleAdmin(admin *sqlparser.Admin) error {
var err error
var result *mysql.Resultset
region := sqlparser.String(admin.Region)
err = c.checkCmdOrder(region, admin.Columns)
if err != nil {
return err
}
switch strings.ToLower(region) {
case NodeRegion:
err = c.handleNodeCmd(admin.Rows)
case ServerRegion:
result, err = c.handleServerCmd(admin.Rows)
default:
return fmt.Errorf("admin %s not supported now", region)
}
if err != nil {
golog.Error("ClientConn", "handleAdmin", err.Error(),
c.connectionId, "sql", sqlparser.String(admin))
return err
}
if result != nil {
return c.writeResultset(c.status, result)
}
return c.writeOK(nil)
}
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 (c *ClientConn) handleNodeCmd(rows sqlparser.InsertRows) error {
var err error
var opt, nodeName, role, addr string
vals := rows.(sqlparser.Values)
if len(vals) == 0 {
return errors.ErrCmdUnsupport
}
tuple := vals[0].(sqlparser.ValTuple)
if len(tuple) != len(cmdNodeOrder) {
return errors.ErrCmdUnsupport
}
opt = sqlparser.String(tuple[0])
opt = strings.Trim(opt, "'")
nodeName = sqlparser.String(tuple[1])
nodeName = strings.Trim(nodeName, "'")
role = sqlparser.String(tuple[2])
role = strings.Trim(role, "'")
addr = sqlparser.String(tuple[3])
addr = strings.Trim(addr, "'")
switch strings.ToLower(opt) {
case ADMIN_OPT_ADD:
err = c.AddDatabase(
nodeName,
role,
addr,
)
case ADMIN_OPT_DEL:
err = c.DeleteDatabase(
nodeName,
role,
addr,
)
case ADMIN_OPT_UP:
err = c.UpDatabase(
nodeName,
role,
addr,
)
case ADMIN_OPT_DOWN:
err = c.DownDatabase(
nodeName,
role,
addr,
)
default:
err = errors.ErrCmdUnsupport
golog.Error("ClientConn", "handleNodeCmd", err.Error(),
c.connectionId, "opt", opt)
}
return err
}
/*生成一个route plan*/
func (r *Router) GetPlan(statement sqlparser.Statement) (plan *Plan) {
plan = &Plan{}
var where *sqlparser.Where
//因为实现Statement接口的方法都是指针类型，所以type对应类型也是指针类型
switch stmt := statement.(type) {
case *sqlparser.Insert:
if _, ok := stmt.Rows.(sqlparser.SelectStatement); ok {
panic(sqlparser.NewParserError("select in insert not allowed"))
}
/*根据sql语句的表，获得对应的分片规则*/
plan.rule = r.GetRule(sqlparser.String(stmt.Table))
if stmt.OnDup != nil {
plan.rule.checkUpdateExprs(sqlparser.UpdateExprs(stmt.OnDup))
}
plan.criteria = plan.routingAnalyzeValues(stmt.Rows.(sqlparser.Values))
plan.fullList = makeList(0, len(plan.rule.Nodes))
return plan
case *sqlparser.Replace:
if _, ok := stmt.Rows.(sqlparser.SelectStatement); ok {
panic(sqlparser.NewParserError("select in replace not allowed"))
}
plan.rule = r.GetRule(sqlparser.String(stmt.Table))
plan.criteria = plan.routingAnalyzeValues(stmt.Rows.(sqlparser.Values))
plan.fullList = makeList(0, len(plan.rule.Nodes))
return plan
case *sqlparser.Select:
plan.rule = r.GetRule(sqlparser.String(stmt.From[0])) //根据表名获得分表规则
where = stmt.Where
case *sqlparser.Update:
plan.rule = r.GetRule(sqlparser.String(stmt.Table))
plan.rule.checkUpdateExprs(stmt.Exprs)
where = stmt.Where
case *sqlparser.Delete:
plan.rule = r.GetRule(sqlparser.String(stmt.Table))
where = stmt.Where
}
if where != nil {
plan.criteria = where.Expr /*路由条件*/
} else {
plan.rule = r.DefaultRule
}
plan.fullList = makeList(0, len(plan.rule.Nodes))
return plan
}
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
plan.TableIndexs = makeList(0, len(plan.Rule.TableToNode))
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.TableIndexs
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{}
stmt := statement.(*sqlparser.Insert)
if _, ok := stmt.Rows.(sqlparser.SelectStatement); ok {
return nil, errors.ErrSelectInInsert
}
/*根据sql语句的表，获得对应的分片规则*/
plan.Rule = r.GetRule(sqlparser.String(stmt.Table))
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))
plan.TableIndexs = makeList(0, len(plan.Rule.TableToNode))
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 (r *Router) buildReplacePlan(db string, 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(db, 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(db string, statement sqlparser.Statement) (*Plan, error) {
plan := &Plan{}
var where *sqlparser.Where
var err error
stmt := statement.(*sqlparser.Delete)
plan.Rule = r.GetRule(db, 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 (c *ClientConn) handleSetAutoCommit(val sqlparser.ValExpr) error {
flag := sqlparser.String(val)
flag = strings.Trim(flag, "'`\"")
// autocommit允许为 0, 1, ON, OFF, "ON", "OFF", 不允许"0", "1"
if flag == `0` || flag == `1` {
_, ok := val.(sqlparser.NumVal)
if !ok {
return fmt.Errorf("set autocommit error")
}
}
switch strings.ToUpper(flag) {
case `1`, `ON`:
c.status |= mysql.SERVER_STATUS_AUTOCOMMIT
if c.status&mysql.SERVER_STATUS_IN_TRANS > 0 {
c.status &= ^mysql.SERVER_STATUS_IN_TRANS
}
for _, co := range c.txConns {
if e := co.SetAutoCommit(1); e != nil {
co.Close()
c.txConns = make(map[*backend.Node]*backend.BackendConn)
return fmt.Errorf("set autocommit error, %v", e)
}
co.Close()
}
c.txConns = make(map[*backend.Node]*backend.BackendConn)
case `0`, `OFF`:
c.status &= ^mysql.SERVER_STATUS_AUTOCOMMIT
default:
return fmt.Errorf("invalid autocommit flag %s", flag)
}
return c.writeOK(nil)
}
func (r *Router) buildDeletePlan(statement sqlparser.Statement) (*Plan, error) {
plan := &Plan{}
var where *sqlparser.Where
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*/
} else {
plan.Rule = r.DefaultRule
}
plan.TableIndexs = makeList(0, len(plan.Rule.TableToNode))
err := plan.calRouteIndexs()
if err != nil {
golog.Error("Route", "BuildDeletePlan", err.Error(), 0)
return nil, err
}
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) buildReplacePlan(statement sqlparser.Statement) (*Plan, error) {
plan := &Plan{}
stmt := statement.(*sqlparser.Replace)
if _, ok := stmt.Rows.(sqlparser.SelectStatement); ok {
panic(sqlparser.NewParserError("select in replace not allowed"))
}
plan.Rule = r.GetRule(sqlparser.String(stmt.Table))
plan.Criteria = plan.checkValuesType(stmt.Rows.(sqlparser.Values))
plan.TableIndexs = makeList(0, len(plan.Rule.TableToNode))
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 (c *ClientConn) handleUseDB(stmt *sqlparser.UseDB) error {
if len(stmt.DB) == 0 {
return fmt.Errorf("must have database, not %s", sqlparser.String(stmt))
}
c.db = string(stmt.DB)
return c.writeOK(nil)
}
func (c *ClientConn) handleServerCmd(rows sqlparser.InsertRows) (*mysql.Resultset, error) {
var err error
var result *mysql.Resultset
var opt, k, v string
vals := rows.(sqlparser.Values)
if len(vals) == 0 {
return nil, errors.ErrCmdUnsupport
}
tuple := vals[0].(sqlparser.ValTuple)
if len(tuple) != len(cmdServerOrder) {
return nil, errors.ErrCmdUnsupport
}
opt = sqlparser.String(tuple[0])
opt = strings.Trim(opt, "'")
k = sqlparser.String(tuple[1])
k = strings.Trim(k, "'")
v = sqlparser.String(tuple[2])
v = strings.Trim(v, "'")
switch strings.ToLower(opt) {
case ADMIN_OPT_SHOW:
result, err = c.handleAdminShow(k, v)
case ADMIN_OPT_CHANGE:
err = c.handleAdminChange(k, v)
case ADMIN_OPT_ADD:
err = c.handleAdminAdd(k, v)
case ADMIN_OPT_DEL:
err = c.handleAdminDelete(k, v)
case ADMIN_SAVE_CONFIG:
err = c.handleAdminSave(k, v)
default:
err = errors.ErrCmdUnsupport
golog.Error("ClientConn", "handleNodeCmd", err.Error(),
c.connectionId, "opt", opt)
}
if err != nil {
return nil, err
}
return result, nil
}
func (r *Router) buildSelectPlan(statement sqlparser.Statement) (*Plan, error) {
plan := &Plan{}
var where *sqlparser.Where
var tableName string
stmt := statement.(*sqlparser.Select)
if ate, ok := (stmt.From[0]).(*sqlparser.AliasedTableExpr); ok {
tableName = sqlparser.String(ate.Expr)
} else {
tableName = sqlparser.String(stmt.From[0])
}
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*/
} else {
plan.Rule = r.DefaultRule
}
plan.TableIndexs = makeList(0, len(plan.Rule.TableToNode))
err := plan.calRouteIndexs()
if err != nil {
golog.Error("Route", "BuildSelectPlan", err.Error(), 0)
return nil, err
}
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) generateInsertSql(plan *Plan, stmt sqlparser.Statement) error {
sqls := make(map[string][]string)
node, ok := stmt.(*sqlparser.Insert)
if ok == false {
return errors.ErrStmtConvert
}
if len(plan.RouteNodeIndexs) == 0 {
return errors.ErrNoRouteNode
}
if len(plan.RouteTableIndexs) == 0 {
buf := sqlparser.NewTrackedBuffer(nil)
stmt.Format(buf)
nodeName := r.Nodes[0]
sqls[nodeName] = []string{buf.String()}
} else {
tableCount := len(plan.RouteTableIndexs)
for i := 0; i < tableCount; i++ {
buf := sqlparser.NewTrackedBuffer(nil)
tableIndex := plan.RouteTableIndexs[i]
nodeIndex := plan.Rule.TableToNode[tableIndex]
nodeName := r.Nodes[nodeIndex]
buf.Fprintf("insert %vinto ", node.Comments)
table := sqlparser.String(node.Table)
if table[len(table)-1] == '`' {
fmt.Fprintf(buf, "%s_%04d`", table[:len(table)-1], plan.RouteTableIndexs[i])
} else {
fmt.Fprintf(buf, "%s_%04d", table, plan.RouteTableIndexs[i])
}
buf.Fprintf("%v %v%v",
node.Columns,
plan.Rows[tableIndex],
node.OnDup)
if _, ok := sqls[nodeName]; ok == false {
sqls[nodeName] = make([]string, 0, tableCount)
}
sqls[nodeName] = append(sqls[nodeName], buf.String())
}
}
plan.RewrittenSqls = sqls
return nil
}
func (c *ClientConn) handleSetNames(val sqlparser.ValExpr) error {
value := sqlparser.String(val)
value = strings.Trim(value, "'`\"")
charset := strings.ToLower(value)
if charset == "null" {
return c.writeOK(nil)
}
cid, ok := mysql.CharsetIds[charset]
if !ok {
return fmt.Errorf("invalid charset %s", charset)
}
c.charset = charset
c.collation = cid
return c.writeOK(nil)
}
func (c *ClientConn) checkCmdOrder(region string, columns sqlparser.Columns) error {
var cmdOrder []string
node := sqlparser.SelectExprs(columns)
switch region {
case NodeRegion:
cmdOrder = cmdNodeOrder
default:
return ErrCmdUnsupport
}
for i := 0; i < len(node); i++ {
val := sqlparser.String(node[i])
if val != cmdOrder[i] {
return ErrCmdUnsupport
}
}
return nil
}
func (r *Router) buildInsertPlan(db string, 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(db, 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)
}
func (r *Router) generateSelectSql(plan *Plan, stmt sqlparser.Statement) error {
sqls := make(map[string][]string)
node, ok := stmt.(*sqlparser.Select)
if ok == false {
return errors.ErrStmtConvert
}
if len(plan.RouteNodeIndexs) == 0 {
return errors.ErrNoRouteNode
}
if len(plan.RouteTableIndexs) == 0 {
buf := sqlparser.NewTrackedBuffer(nil)
stmt.Format(buf)
nodeName := r.Nodes[0]
sqls[nodeName] = []string{buf.String()}
} else {
tableCount := len(plan.RouteTableIndexs)
for i := 0; i < tableCount; i++ {
buf := sqlparser.NewTrackedBuffer(nil)
buf.Fprintf("select %v%s%v from ",
node.Comments,
node.Distinct,
node.SelectExprs,
)
if ate, ok := (node.From[0]).(*sqlparser.AliasedTableExpr); ok {
if len(ate.As) != 0 {
fmt.Fprintf(buf, "%s_%04d AS %s",
sqlparser.String(ate.Expr),
plan.RouteTableIndexs[i],
string(ate.As),
)
} else {
fmt.Fprintf(buf, "%s_%04d",
sqlparser.String(ate.Expr),
plan.RouteTableIndexs[i],
)
}
} else {
fmt.Fprintf(buf, "%s_%04d",
sqlparser.String(node.From[0]),
plan.RouteTableIndexs[i],
)
}
buf.Fprintf("%v%v%v%v%v%s",
node.Where,
node.GroupBy,
node.Having,
node.OrderBy,
node.Limit,
node.Lock,
)
tableIndex := plan.RouteTableIndexs[i]
nodeIndex := plan.Rule.TableToNode[tableIndex]
nodeName := r.Nodes[nodeIndex]
if _, ok := sqls[nodeName]; ok == false {
sqls[nodeName] = make([]string, 0, tableCount)
}
sqls[nodeName] = append(sqls[nodeName], buf.String())
}
}
plan.RewrittenSqls = sqls
return 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,
)
}
buf.Fprintf("%v%v%v%v%s",
node.Where,
node.GroupBy,
node.Having,
node.OrderBy,
node.Lock,
)
return buf.String()
}
//rewrite select sql
func (r *Router) rewriteSelectSql(plan *Plan, node *sqlparser.Select, tableIndex int) string {
buf := sqlparser.NewTrackedBuffer(nil)
buf.Fprintf("select %v%s",
node.Comments,
node.Distinct,
)
var prefix string
//rewrite select expr
for _, expr := range node.SelectExprs {
switch v := expr.(type) {
case *sqlparser.StarExpr:
//for shardTable.*,need replace table into shardTable_xxxx.
if string(v.TableName) == plan.Rule.Table {
fmt.Fprintf(buf, "%s%s_%04d.*",
prefix,
plan.Rule.Table,
tableIndex,
)
} else {
buf.Fprintf("%s%v", prefix, expr)
}
case *sqlparser.NonStarExpr:
//rewrite shardTable.column as a
//into shardTable_xxxx.column as a
if colName, ok := v.Expr.(*sqlparser.ColName); ok {
if string(colName.Qualifier) == plan.Rule.Table {
fmt.Fprintf(buf, "%s%s_%04d.%s",
prefix,
plan.Rule.Table,
tableIndex,
string(colName.Name),
)
} else {
buf.Fprintf("%s%v", prefix, colName)
}
//if expr has as
if v.As != nil {
buf.Fprintf(" as %s", v.As)
}
} else {
buf.Fprintf("%s%v", prefix, expr)
}
default:
buf.Fprintf("%s%v", prefix, expr)
}
prefix = ", "
}
//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])
}
newLimit, err := node.Limit.RewriteLimit()
if err != nil {
//do not change limit
newLimit = node.Limit
}
//rewrite where
oldright, err := plan.rewriteWhereIn(tableIndex)
buf.Fprintf("%v%v%v%v%v%s",
node.Where,
node.GroupBy,
node.Having,
node.OrderBy,
newLimit,
node.Lock,
)
//restore old right
if oldright != nil {
plan.InRightToReplace.Right = oldright
}
return buf.String()
}