func (t *dbTables) get(name string) (*dbTable, bool) {
	j, ok := t.tablesM[name]
	return j, ok
}
get table info in collection.
package orm
import (
	"fmt"
	"strings"
	"time"
)
type dbTable struct {
	id    int
	index string
	name  string
	names []string
	sel   bool
	inner bool
	mi    *modelInfo
	fi    *fieldInfo
	jtl   *dbTable
}
type dbTables struct {
	tablesM map[string]*dbTable
	tables  []*dbTable
	mi      *modelInfo
	base    dbBaser
	skipEnd bool
}
func (t *dbTables) set(names []string, mi *modelInfo, fi *fieldInfo, inner bool) *dbTable {
	name := strings.Join(names, ExprSep)
	if j, ok := t.tablesM[name]; ok {
		j.name = name
		j.mi = mi
		j.fi = fi
		j.inner = inner
	} else {
		i := len(t.tables) + 1
		jt := &dbTable{i, fmt.Sprintf("T%d", i), name, names, false, inner, mi, fi, nil}
		t.tablesM[name] = jt
		t.tables = append(t.tables, jt)
	}
	return t.tablesM[name]
}
func (t *dbTables) add(names []string, mi *modelInfo, fi *fieldInfo, inner bool) (*dbTable, bool) {
	name := strings.Join(names, ExprSep)
	if _, ok := t.tablesM[name]; ok == false {
		i := len(t.tables) + 1
		jt := &dbTable{i, fmt.Sprintf("T%d", i), name, names, false, inner, mi, fi, nil}
		t.tablesM[name] = jt
		t.tables = append(t.tables, jt)
		return jt, true
	}
	return t.tablesM[name], false
}