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DB_common::tableInfo()

DB_common::tableInfo() -- Get info about columns in a table or a query result

Synopsis

array tableInfo (mixed $result [, int $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

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

integer $mode

one of the tableInfo mode constants

Return value

Returns an associative array of column information. DB_Error object if problems arise.

The array's contents depends on the mode parameter.

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

Table 21-1. Possible PEAR_Error values

Error code	Error message	Reason	Solution
`DB_ERROR_NOT_CAPABLE`	`NULL`	Driver doesn't support this feature.	Switch to another database system, if you really need this feature.
`DB_ERROR_NEED_MORE_DATA`	`NULL`	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`	`NULL`	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 capability and the data returned by each DBMS varies wildly.

Example

Example 21-1. Finding information about a table

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

Example 21-2. Finding information about a query result

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

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