github.com/zhongdalu/gf@v1.0.0/g/database/gdb/gdb_pgsql.go (about)

     1  // Copyright 2017 gf Author(https://github.com/zhongdalu/gf). All Rights Reserved.
     2  //
     3  // This Source Code Form is subject to the terms of the MIT License.
     4  // If a copy of the MIT was not distributed with this file,
     5  // You can obtain one at https://github.com/zhongdalu/gf.
     6  
     7  package gdb
     8  
     9  import (
    10  	"database/sql"
    11  	"fmt"
    12  
    13  	"github.com/zhongdalu/gf/g/text/gregex"
    14  )
    15  
    16  // PostgreSQL的适配.
    17  //
    18  // 使用时需要import:
    19  //
    20  // _ "github.com/zhongdalu/gf/third/github.com/lib/pq"
    21  //
    22  // @todo 需要完善replace和save的操作覆盖
    23  
    24  // 数据库链接对象
    25  type dbPgsql struct {
    26  	*dbBase
    27  }
    28  
    29  // 创建SQL操作对象，内部采用了lazy link处理
    30  func (db *dbPgsql) Open(config *ConfigNode) (*sql.DB, error) {
    31  	var source string
    32  	if config.LinkInfo != "" {
    33  		source = config.LinkInfo
    34  	} else {
    35  		source = fmt.Sprintf("user=%s password=%s host=%s port=%s dbname=%s", config.User, config.Pass, config.Host, config.Port, config.Name)
    36  	}
    37  	if db, err := sql.Open("postgres", source); err == nil {
    38  		return db, nil
    39  	} else {
    40  		return nil, err
    41  	}
    42  }
    43  
    44  // 动态切换数据库
    45  func (db *dbPgsql) setSchema(sqlDb *sql.DB, schema string) error {
    46  	_, err := sqlDb.Exec("SET search_path TO " + schema)
    47  	return err
    48  }
    49  
    50  // 获得关键字操作符
    51  func (db *dbPgsql) getChars() (charLeft string, charRight string) {
    52  	return "\"", "\""
    53  }
    54  
    55  // 在执行sql之前对sql进行进一步处理
    56  func (db *dbPgsql) handleSqlBeforeExec(query string) string {
    57  	index := 0
    58  	query, _ = gregex.ReplaceStringFunc("\\?", query, func(s string) string {
    59  		index++
    60  		return fmt.Sprintf("$%d", index)
    61  	})
    62  	// 分页语法替换
    63  	query, _ = gregex.ReplaceString(` LIMIT (\d+),\s*(\d+)`, ` LIMIT $1 OFFSET $2`, query)
    64  	return query
    65  }