# pg_escape_identifier

(PHP 5 >= 5.4.4, PHP 7)

pg_escape_identifier — Escape a identifier for insertion into a text field

### 说明

pg_escape_identifier ([ resource `$connection` ], string `$data` ) : string

pg_escape_identifier() escapes a identifier (e.g. table, field names) for quering the database. It returns an escaped identifier string for PostgreSQL server. pg_escape_identifier() adds double quotes before and after data. Users should not add double quotes. Use of this function is recommended for identifier parameters in query. For SQL literals (i.e. parameters except bytea), pg_escape_literal() or pg_escape_string() must be used. For bytea type fields, pg_escape_bytea() must be used instead.

> Note:

> This function has internal escape code and can also be used with PostgreSQL 8.4 or less.

### 参数

`connection`

  PostgreSQL database connection resource. When `connection` is not present, the default connection is used. The default connection is the last connection made by pg_connect() or pg_pconnect().

`data`

  A string containing text to be escaped.

### 返回值

A string containing the escaped data.

### 范例

Example #1 pg_escape_identifier() example

    <?php
      // Connect to the database
      $dbconn = pg_connect('dbname=foo');

      // Escape the table name data
      $escaped = pg_escape_identifier($table_name);

      // Select rows from $table_name
      pg_query("SELECT * FROM {$escaped};");
    ?>

### 参见

- pg_escape_literal() - Escape a literal for insertion into a text field
- pg_escape_bytea() - 转义 bytea 类型的二进制数据
- pg_escape_string() - 转义 text/char 类型的字符串