DB_common::tableInfo()

DB_common::tableInfo() – Gets info about columns in a table or a query result

Synopsis

array tableInfo ( mixed $result , integer $mode = null )

Description

Get information about columns in a table or a query result.

Parameter

mixed $result

DB_result object from a query or a string containing the name of a table

If the name of the table needs to be delimited (ie: the name is a reserved word or has spaces in it), use the quoteIdentifier() method on the table name when passing it.

This can also be a query result resource identifier, but doing so is deprecated.

integer $mode

one of the tableInfo mode constants

Return value

array - an associative array of the table's information or a DB_Error object on failure

The array's contents depends on the $mode parameter.

The names of tables and columns will be lowercased if the DB_PORTABILITY_LOWERCASE portability mode is enabled.

The flags element contains a space separated list of extra information about the column. If the DBMS is able to report a column's default value, the value is passed through rawurlencode() to avoid problems caused by potential spaces in the value.

Most DBMS's only provide the table and flags elements if $result is a table name. Only fbsql and mysql provide full information from queries.

The type element contains the type returned by the DBMS. It varies from DBMS to DBMS.

tableInfo Modes

This section describes the format of the returned array and how it varies depending on which $mode was used when the function was called.

The sample output below is based on this query:

SELECT tblFoo.fldID, tblFoo.fldPhone, tblBar.fldId
  FROM tblFoo
  JOIN tblBar ON tblFoo.fldId = tblBar.fldId;

NULL or 0


[0] => Array (
  [table] => tblFoo
  [name] => fldId
  [type] => int
  [len] => 11
  [flags] => primary_key not_null
)
[1] => Array (
  [table] => tblFoo
  [name] => fldPhone
  [type] => string
  [len] => 20
  [flags] =>
)
[2] => Array (
  [table] => tblBar
  [name] => fldId
  [type] => int
  [len] => 11
  [flags] => primary_key not_null
)
DB_TABLEINFO_ORDER

In addition to the information found in the default output, a notation of the number of columns is provided by the num_fields element while the order element provides an array with the column names as the keys and their location index number (corresponding to the keys in the default output) as the values.

If a result set has identical field names, the last one is used.


[num_fields] => 3
[order] => Array (
  [fldId] => 2
  [fldTrans] => 1
)
DB_TABLEINFO_ORDERTABLE

Similar to DB_TABLEINFO_ORDER but adds more dimensions to the array in which the table names are keys and the field names are sub-keys. This is helpful for queries that join tables which have identical field names.


[num_fields] => 3
[ordertable] => Array (
  [tblFoo] => Array (
      [fldId] => 0
      [fldPhone] => 1
  )
  [tblBar] => Array (
      [fldId] => 2
  )
)
DB_TABLEINFO_FULL

Contains the information from both DB_TABLEINFO_ORDER and DB_TABLEINFO_ORDERTABLE

The tableInfo mode constants are bitwised, so they can be combined using |.

Throws

Possible PEAR_Error values
Error code Error message Reason Solution
DB_ERROR_NOT_CAPABLE DB backend not capable Driver doesn't support this feature. Switch to another database system, if you really need this feature.
DB_ERROR_NEED_MORE_DATA insufficient data supplied The data passed in the $result parameter was not a valid table name or result identifier. Check the table name for typographical errors or that the query ran correctly.
DB_ERROR_NODBSELECTED no database selected No database was chosen. Check the DSN in connect().
can't distinguish duplicate field names   The query result has multiple columns with the same name. PHP's Informix extension deals with columns having the same names by overwriting the prior columns information. Therefore, tableInfo() is unable to properly represent these result sets. Use aliases for columns that have the same names.

Note

This function can not be called statically.

tableInfo() is not portable because not all drivers have this method, many DBMS's are unable to determine table names from query results and the metadata returned by each database system varies dramatically.

Example

Finding information about a table

<?php
// Once you have a valid DB object named $db...
$info $db->tableInfo('tablename');
print_r($info);
?>

Finding information about a query result

<?php
// Once you have a valid DB object named $db...
$res  =& $db->query('SELECT * FROM tablename');
$info =  $db->tableInfo($res);
print_r($info);
?>

Prior to version 1.6.0, tableInfo() was a part of the DB_result class, so had to be called like this:

<?php
// Once you have a valid DB object named $db...
$res  =& $db->query('SELECT * FROM tablename');
$info =  $res->tableInfo();  // <---- DEPRECATED
print_r($info);
?>

Sets run-time configuration options for PEAR DB (Previous) DB result set (Next)
Last updated: Sun, 21 Dec 2014 — Download Documentation
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