# pg_result_error_field

(PHP 5 >= 5.1.0, PHP 7)

pg_result_error_field — Returns an individual field of an error report

### 说明

pg_result_error_field ( resource `$result` , int `$fieldcode` ) : string

pg_result_error_field() returns one of the detailed error message fields associated with `result` resource. It is only available against a PostgreSQL 7.4 or above server. The error field is specified by the `fieldcode`.

Because pg_query() and pg_query_params() return `FALSE` if the query fails, you must use pg_send_query() and pg_get_result() to get the result handle.

If you need to get additional error information from failed pg_query() queries, use pg_set_error_verbosity() and pg_last_error() and then parse the result.

### 参数

`result`

  A PostgreSQL query result resource from a previously executed statement.

`fieldcode`

  Possible `fieldcode` values are: `PGSQL_DIAG_SEVERITY`, `PGSQL_DIAG_SQLSTATE`, `PGSQL_DIAG_MESSAGE_PRIMARY`, `PGSQL_DIAG_MESSAGE_DETAIL`, `PGSQL_DIAG_MESSAGE_HINT`, `PGSQL_DIAG_STATEMENT_POSITION`, `PGSQL_DIAG_INTERNAL_POSITION` (PostgreSQL 8.0+ only), `PGSQL_DIAG_INTERNAL_QUERY` (PostgreSQL 8.0+ only), `PGSQL_DIAG_CONTEXT`, `PGSQL_DIAG_SOURCE_FILE`, `PGSQL_DIAG_SOURCE_LINE` or `PGSQL_DIAG_SOURCE_FUNCTION`.

### 返回值

A string containing the contents of the error field, `NULL` if the field does not exist or `FALSE` on failure.

### 范例

Example #1 pg_result_error_field() example

    <?php
      $dbconn = pg_connect("dbname=publisher") or die("Could not connect");

      if (!pg_connection_busy($dbconn)) {
          pg_send_query($dbconn, "select * from doesnotexist;");
      }

      $res1 = pg_get_result($dbconn);
      echo pg_result_error_field($res1, PGSQL_DIAG_SQLSTATE);
    ?>

### 参见

- pg_result_error() - 获得查询结果的错误信息