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Beego/orm/db_tables.go
2014-01-17 17:25:17 +08:00

439 lines
8.3 KiB
Go

package orm
import (
"fmt"
"strings"
"time"
)
// table info struct.
type dbTable struct {
id int
index string
name string
names []string
sel bool
inner bool
mi *modelInfo
fi *fieldInfo
jtl *dbTable
}
// tables collection struct, contains some tables.
type dbTables struct {
tablesM map[string]*dbTable
tables []*dbTable
mi *modelInfo
base dbBaser
skipEnd bool
}
// set table info to collection.
// if not exist, create new.
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]
}
// add table info to collection.
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
}
// get table info in collection.
func (t *dbTables) get(name string) (*dbTable, bool) {
j, ok := t.tablesM[name]
return j, ok
}
// get related fields info in recursive depth loop.
// loop once, depth decreases one.
func (t *dbTables) loopDepth(depth int, prefix string, fi *fieldInfo, related []string) []string {
if depth < 0 || fi.fieldType == RelManyToMany {
return related
}
if prefix == "" {
prefix = fi.name
} else {
prefix = prefix + ExprSep + fi.name
}
related = append(related, prefix)
depth--
for _, fi := range fi.relModelInfo.fields.fieldsRel {
related = t.loopDepth(depth, prefix, fi, related)
}
return related
}
// parse related fields.
func (t *dbTables) parseRelated(rels []string, depth int) {
relsNum := len(rels)
related := make([]string, relsNum)
copy(related, rels)
relDepth := depth
if relsNum != 0 {
relDepth = 0
}
relDepth--
for _, fi := range t.mi.fields.fieldsRel {
related = t.loopDepth(relDepth, "", fi, related)
}
for i, s := range related {
var (
exs = strings.Split(s, ExprSep)
names = make([]string, 0, len(exs))
mmi = t.mi
cancel = true
jtl *dbTable
)
inner := true
for _, ex := range exs {
if fi, ok := mmi.fields.GetByAny(ex); ok && fi.rel && fi.fieldType != RelManyToMany {
names = append(names, fi.name)
mmi = fi.relModelInfo
if fi.null || t.skipEnd {
inner = false
}
jt := t.set(names, mmi, fi, inner)
jt.jtl = jtl
if fi.reverse {
cancel = false
}
if cancel {
jt.sel = depth > 0
if i < relsNum {
jt.sel = true
}
}
jtl = jt
} else {
panic(fmt.Errorf("unknown model/table name `%s`", ex))
}
}
}
}
// generate join string.
func (t *dbTables) getJoinSql() (join string) {
Q := t.base.TableQuote()
for _, jt := range t.tables {
if jt.inner {
join += "INNER JOIN "
} else {
join += "LEFT OUTER JOIN "
}
var (
table string
t1, t2 string
c1, c2 string
)
t1 = "T0"
if jt.jtl != nil {
t1 = jt.jtl.index
}
t2 = jt.index
table = jt.mi.table
switch {
case jt.fi.fieldType == RelManyToMany || jt.fi.reverse && jt.fi.reverseFieldInfo.fieldType == RelManyToMany:
c1 = jt.fi.mi.fields.pk.column
for _, ffi := range jt.mi.fields.fieldsRel {
if jt.fi.mi == ffi.relModelInfo {
c2 = ffi.column
break
}
}
default:
c1 = jt.fi.column
c2 = jt.fi.relModelInfo.fields.pk.column
if jt.fi.reverse {
c1 = jt.mi.fields.pk.column
c2 = jt.fi.reverseFieldInfo.column
}
}
join += fmt.Sprintf("%s%s%s %s ON %s.%s%s%s = %s.%s%s%s ", Q, table, Q, t2,
t2, Q, c2, Q, t1, Q, c1, Q)
}
return
}
// parse orm model struct field tag expression.
func (t *dbTables) parseExprs(mi *modelInfo, exprs []string) (index, name string, info *fieldInfo, success bool) {
var (
jtl *dbTable
fi *fieldInfo
fiN *fieldInfo
mmi = mi
)
num := len(exprs) - 1
names := make([]string, 0)
inner := true
loopFor:
for i, ex := range exprs {
var ok, okN bool
if fiN != nil {
fi = fiN
ok = true
fiN = nil
}
if i == 0 {
fi, ok = mmi.fields.GetByAny(ex)
}
_ = okN
if ok {
isRel := fi.rel || fi.reverse
names = append(names, fi.name)
switch {
case fi.rel:
mmi = fi.relModelInfo
if fi.fieldType == RelManyToMany {
mmi = fi.relThroughModelInfo
}
case fi.reverse:
mmi = fi.reverseFieldInfo.mi
}
if i < num {
fiN, okN = mmi.fields.GetByAny(exprs[i+1])
}
if isRel && (fi.mi.isThrough == false || num != i) {
if fi.null || t.skipEnd {
inner = false
}
if t.skipEnd && okN || !t.skipEnd {
if t.skipEnd && okN && fiN.pk {
goto loopEnd
}
jt, _ := t.add(names, mmi, fi, inner)
jt.jtl = jtl
jtl = jt
}
}
if num != i {
continue
}
loopEnd:
if i == 0 || jtl == nil {
index = "T0"
} else {
index = jtl.index
}
info = fi
if jtl == nil {
name = fi.name
} else {
name = jtl.name + ExprSep + fi.name
}
switch {
case fi.rel:
case fi.reverse:
switch fi.reverseFieldInfo.fieldType {
case RelOneToOne, RelForeignKey:
index = jtl.index
info = fi.reverseFieldInfo.mi.fields.pk
name = info.name
}
}
break loopFor
} else {
index = ""
name = ""
info = nil
success = false
return
}
}
success = index != "" && info != nil
return
}
// generate condition sql.
func (t *dbTables) getCondSql(cond *Condition, sub bool, tz *time.Location) (where string, params []interface{}) {
if cond == nil || cond.IsEmpty() {
return
}
Q := t.base.TableQuote()
mi := t.mi
for i, p := range cond.params {
if i > 0 {
if p.isOr {
where += "OR "
} else {
where += "AND "
}
}
if p.isNot {
where += "NOT "
}
if p.isCond {
w, ps := t.getCondSql(p.cond, true, tz)
if w != "" {
w = fmt.Sprintf("( %s) ", w)
}
where += w
params = append(params, ps...)
} else {
exprs := p.exprs
num := len(exprs) - 1
operator := ""
if operators[exprs[num]] {
operator = exprs[num]
exprs = exprs[:num]
}
index, _, fi, suc := t.parseExprs(mi, exprs)
if suc == false {
panic(fmt.Errorf("unknown field/column name `%s`", strings.Join(p.exprs, ExprSep)))
}
if operator == "" {
operator = "exact"
}
operSql, args := t.base.GenerateOperatorSql(mi, fi, operator, p.args, tz)
leftCol := fmt.Sprintf("%s.%s%s%s", index, Q, fi.column, Q)
t.base.GenerateOperatorLeftCol(fi, operator, &leftCol)
where += fmt.Sprintf("%s %s ", leftCol, operSql)
params = append(params, args...)
}
}
if sub == false && where != "" {
where = "WHERE " + where
}
return
}
// generate order sql.
func (t *dbTables) getOrderSql(orders []string) (orderSql string) {
if len(orders) == 0 {
return
}
Q := t.base.TableQuote()
orderSqls := make([]string, 0, len(orders))
for _, order := range orders {
asc := "ASC"
if order[0] == '-' {
asc = "DESC"
order = order[1:]
}
exprs := strings.Split(order, ExprSep)
index, _, fi, suc := t.parseExprs(t.mi, exprs)
if suc == false {
panic(fmt.Errorf("unknown field/column name `%s`", strings.Join(exprs, ExprSep)))
}
orderSqls = append(orderSqls, fmt.Sprintf("%s.%s%s%s %s", index, Q, fi.column, Q, asc))
}
orderSql = fmt.Sprintf("ORDER BY %s ", strings.Join(orderSqls, ", "))
return
}
// generate limit sql.
func (t *dbTables) getLimitSql(mi *modelInfo, offset int64, limit int64) (limits string) {
if limit == 0 {
limit = int64(DefaultRowsLimit)
}
if limit < 0 {
// no limit
if offset > 0 {
maxLimit := t.base.MaxLimit()
if maxLimit == 0 {
limits = fmt.Sprintf("OFFSET %d", offset)
} else {
limits = fmt.Sprintf("LIMIT %d OFFSET %d", maxLimit, offset)
}
}
} else if offset <= 0 {
limits = fmt.Sprintf("LIMIT %d", limit)
} else {
limits = fmt.Sprintf("LIMIT %d OFFSET %d", limit, offset)
}
return
}
// crete new tables collection.
func newDbTables(mi *modelInfo, base dbBaser) *dbTables {
tables := &dbTables{}
tables.tablesM = make(map[string]*dbTable)
tables.mi = mi
tables.base = base
return tables
}