ADOdb

Database Abstraction Layer for PHP

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v5:database:text

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This driver is broken in ADOdb version 5 when used with PHP version 5.3 and up. This is due to the fact that the execute method has a non-compliant 3rd argument to it. Absent any user requests, this driver will be removed in ADOdb version 6.

Description

The text driver allows an array of data to be processed like a read-only database table. The connect statement provides the data, as well as information about columns and names. No meta functions are supported. The *WHERE* SQL statement is ignored. In order to filter requests, An eval'd expression must be passed as a third argument.


Syntax
object connect(
      array $dataArray,
      optional mixed $dataTypes=false,
      optional mixec $columnNames=false
      )

The Connect Statement

Parameters

$dataArray

This is a 2 dimensional array of data. Optionally, the first row may contain the column names. If column names are not defined in first row, they must be defined in the third argument $columnNames.

$dataTypes

The optional parameter $dataTypes provides an array of metaTypes that match the columns in the table. This array forces a type onto each column. If the array is not provided, the driver probes each column in an attempt to discern the data types in the column. If results are ambiguous, the driver assigns a metaType of 'C'. Better results are always obtained if the column types are defined, because the driver only recognize C, I and N types.


Column names, whether provided in the first row of data or in the $columnNames array, must be upper case.

$columnNames

If the first row of the data array is not column names, the $columnNames parameter must provide a array of column names.

If provided, the number of columns in the 2nd and 3rd arguments must exactly match the number in the first.


Syntax
mixed execute(
      string $sql
     optional bool $ignored=false
     optional string $evalStatement=false
      )

execute

The execute() method will return a recordset. The recordset works like a normal recordset.

There is partial support for SQL parsing. We process the SQL using the following rules:

  1. SQL ORDER BY's always work for the first column ordered. Subsequent cols are ignored.
  2. All operations take place on the same table. In fact the FROM clause is ignored, you can use any name for the table.
  1. To simplify code, all columns are returned, except when selecting 1 column.
$rs = $db->execute('select col1,col2 from table'); // sql ignored, will generate all cols
$rs = $db->execute('select col1 from table');
// sql accepted and processed -- any table name is accepted
$rs = $db->execute('select distinct col1 from table');
// sql accepted and processed

Where clauses are ignored, but searching with the 3rd parameter of execute() is permitted.


Using eval may make code susceptible to SQL injection attacks.

Using an eval statement

The 3rd argument to execute has to use PHP syntax and the driver will attempt to eval() it. You can even use PHP functions, for example


// 3rd parameter is evaled PHP code, not SQL, so watch the '==' vs. '='
$rs = $db->execute('select * from table', false, "\$COL1=='abc' and \$COL2==3");

Limitations

The following SQL operations are not supported:

  • GROUP BY, HAVING, other clauses
  • Expression columns such as min(), max()
  • Joins are not permitted

Usage

include 'adodb/adodb.inc.php';
 
$data = array(
      0=>array(10001,'1953-09-02','Georgi','Facello','M','1986-06-26'),
      1=>array(10002,'1964-06-02','Bezalel','Simmel','F','1985-11-21'),
      2=>array(10003,'1959-12-03','Parto','Bamford','M','1986-08-28'),
      3=>array(10004,'1954-05-01','Christian','Koblick','M','1986-12-01'),
      4=>array(10005,'1955-01-21','Kyoichi','Maliniak', 'M','1989-09-12'),
      5=>array(10006,'1953-04-20','Anneke','Preusig','F','1989-06-02')
);
 
$cols = array('EMPNO','BIRTH_DATE','FIRST_NAME','LAST_NAME','SEX','HIRE_DATE');
$metaTypes = array('I','D','C','C','C','D');
 
$db = ADONewConnection('text');
 
$db->connect($data, $metaTypes, $cols);
 
$sql = 'select * from table';
 
// Does not work with PHP 5.3 or later, see workaround below
$result = $db->execute($sql, false, "\$EMPNO==10005");
 
while ($r = $result->fetchRow()) {
  print_r($r);
}

Workaround

For PHP 5.3 or later, the following workaround can be used (tested with ADOdb 5.20.15).

Replace the $result = $db→execute($sql, false, “\$EMPNO==10005”); statement in the above sample by the following code.

$db->evalAll = "\$EMPNO==10005";
$result = $db->execute($sql);
$db->evalAll = false;
v5/database/text.txt · Last modified: 2020/01/13 13:17 by dregad