gf/database/gdb/gdb_driver_pgsql.go
2020-10-12 23:22:56 +08:00

150 lines
4.4 KiB
Go

// Copyright 2017 gf Author(https://github.com/gogf/gf). All Rights Reserved.
//
// This Source Code Form is subject to the terms of the MIT License.
// If a copy of the MIT was not distributed with this file,
// You can obtain one at https://github.com/gogf/gf.
//
// Note:
// 1. It needs manually import: _ "github.com/lib/pq"
// 2. It does not support Save/Replace features.
// 3. It does not support LastInsertId.
package gdb
import (
"database/sql"
"errors"
"fmt"
"github.com/gogf/gf/internal/intlog"
"github.com/gogf/gf/os/gcache"
"github.com/gogf/gf/text/gstr"
"strings"
"github.com/gogf/gf/text/gregex"
)
// DriverPgsql is the driver for postgresql database.
type DriverPgsql struct {
*Core
}
// New creates and returns a database object for postgresql.
// It implements the interface of gdb.Driver for extra database driver installation.
func (d *DriverPgsql) New(core *Core, node *ConfigNode) (DB, error) {
return &DriverPgsql{
Core: core,
}, nil
}
// Open creates and returns a underlying sql.DB object for pgsql.
func (d *DriverPgsql) Open(config *ConfigNode) (*sql.DB, error) {
var source string
if config.LinkInfo != "" {
source = config.LinkInfo
} else {
source = fmt.Sprintf(
"user=%s password=%s host=%s port=%s dbname=%s sslmode=disable",
config.User, config.Pass, config.Host, config.Port, config.Name,
)
}
intlog.Printf("Open: %s", source)
if db, err := sql.Open("postgres", source); err == nil {
return db, nil
} else {
return nil, err
}
}
// GetChars returns the security char for this type of database.
func (d *DriverPgsql) GetChars() (charLeft string, charRight string) {
return "\"", "\""
}
// HandleSqlBeforeCommit deals with the sql string before commits it to underlying sql driver.
func (d *DriverPgsql) HandleSqlBeforeCommit(link Link, sql string, args []interface{}) (string, []interface{}) {
var index int
// Convert place holder char '?' to string "$x".
sql, _ = gregex.ReplaceStringFunc("\\?", sql, func(s string) string {
index++
return fmt.Sprintf("$%d", index)
})
sql, _ = gregex.ReplaceString(` LIMIT (\d+),\s*(\d+)`, ` LIMIT $2 OFFSET $1`, sql)
return sql, args
}
// Tables retrieves and returns the tables of current schema.
// It's mainly used in cli tool chain for automatically generating the models.
func (d *DriverPgsql) Tables(schema ...string) (tables []string, err error) {
var result Result
link, err := d.DB.GetSlave(schema...)
if err != nil {
return nil, err
}
query := "SELECT TABLENAME FROM PG_TABLES WHERE SCHEMANAME = 'public' ORDER BY TABLENAME"
if len(schema) > 0 && schema[0] != "" {
query = fmt.Sprintf("SELECT TABLENAME FROM PG_TABLES WHERE SCHEMANAME = '%s' ORDER BY TABLENAME", schema[0])
}
result, err = d.DB.DoGetAll(link, query)
if err != nil {
return
}
for _, m := range result {
for _, v := range m {
tables = append(tables, v.String())
}
}
return
}
// TableFields retrieves and returns the fields information of specified table of current schema.
func (d *DriverPgsql) TableFields(table string, schema ...string) (fields map[string]*TableField, err error) {
charL, charR := d.GetChars()
table = gstr.Trim(table, charL+charR)
if gstr.Contains(table, " ") {
return nil, errors.New("function TableFields supports only single table operations")
}
table, _ = gregex.ReplaceString("\"", "", table)
checkSchema := d.DB.GetSchema()
if len(schema) > 0 && schema[0] != "" {
checkSchema = schema[0]
}
v, _ := gcache.GetOrSetFunc(
fmt.Sprintf(`pgsql_table_fields_%s_%s`, table, checkSchema),
func() (interface{}, error) {
var (
result Result
link *sql.DB
)
link, err = d.DB.GetSlave(checkSchema)
if err != nil {
return nil, err
}
structureSql := fmt.Sprintf(`
SELECT a.attname AS field, t.typname AS type FROM pg_class c, pg_attribute a
LEFT OUTER JOIN pg_description b ON a.attrelid=b.objoid AND a.attnum = b.objsubid,pg_type t
WHERE c.relname = '%s' and a.attnum > 0 and a.attrelid = c.oid and a.atttypid = t.oid
ORDER BY a.attnum`,
strings.ToLower(table),
)
structureSql, _ = gregex.ReplaceString(`[\n\r\s]+`, " ", gstr.Trim(structureSql))
result, err = d.DB.DoGetAll(link, structureSql)
if err != nil {
return nil, err
}
fields = make(map[string]*TableField)
for i, m := range result {
fields[m["field"].String()] = &TableField{
Index: i,
Name: m["field"].String(),
Type: m["type"].String(),
}
}
return fields, nil
}, 0)
if err == nil {
fields = v.(map[string]*TableField)
}
return
}