I'm learning PowerShell scripting & want to extract tableName from SQL Query String. For example, I've this query -
$q = "SELECT * FROM [TestDB].[dbo].Invoice_Details where Clientname='ABC'"
where I want to extract table name i.e. it should output this - Invoice_Details
Currently, I'm doing this with following working code -
$q1 = $q -split '\[dbo\]\.'
$q2 = $q1[1] -split ' where '
write-host $q2[0] #here I get it right (Invoice_Details)
But, sometimes the query may/ may not have bracketed names like - [TestDB].[dbo].
So, I want to optimize this code so that it will work even if query containing any combination of bracketed/ bracketless tableNames
Try something like this:
$res = ([regex]'(?is)\b(?:from|into|update)\s+(\[?.+\]?\.)?\[?(\[?\w+)\]?').Matches($q)
write-host $res[0].Groups[2].Value
Related
I try to create advanced search to my database.
I want to do something like that: if the user type for search = overf**w
and I have in my database an cloumn that his value = overflow - show him.
this my code:
$name = str_replace('*', '_', $name);
SELECT name FROM table WHERE name LIKE CONCAT('%', ?, '%')
its not working, I dont know what the problem.
You can't use LIKE in this situation, you need to use REGEXP() to do a wildcard search. Replace * or ** with .*. To only return names that starts with the given value use ^ at the beginning of the regular expression
SELECT name
FROM actors
WHERE name REGEXP('^overf.*w')
I don't know php but your $name parameter should be set like this (in pseudo code)
$name = '^' + replace($name, '**', '.*')
I am able to replace a single string in a SQL file using PowerShell as follows:
$newPrefix = "foo'
$dbUserMappingScriptPath = "C:\MySQL_Template.sql"
$updatedDbUserMapingScriptPath = "C:\MySQL.sql"
(gc $dbUserMappingScriptPath).Replace('DBPrefix_',$newPrefix) | sc $updatedDbUserMapingScriptPath
This is great for single scenarios, but I need to replace multiple strings. I have tried the following, but it doesn't perform the replace operation beyond replacing the first string of 'DBPrefix_' with $newPrefix. It does not perform the replacements for 'MDFDatabasePath' and 'LDFDatabasePath'.
How do I replace multiple strings given the following snippet? Note that this is wrapped in a Foreach-Object for the $.MDFDatabasePath and $.LDFDatabasePath values.
$dbUserMappingScriptPath = "C:\MySQL_Template.sql"
$updatedDbUserMapingScriptPath = "C:\MySQL.sql"
(gc $dbUserMappingScriptPath).Replace('DBPrefix_',$newPrefix).Replace('MDFDatabasePath',$_.MDFDatabasePath).Replace('LDFDatabasePath',$_.LDFDatabasePath) | sc $updatedDbUserMapingScriptPath
Here is a snippet of my SQL:
USE [master]
GO
CREATE DATABASE [DBPrefix_mydb] ON
( FILENAME = N'MDFDatabasePath\DBPrefix_mydb.MDF' ),
( FILENAME = N'LDFDatabasePath\DBPrefix_mydb.ldf' )
FOR ATTACH
GO
UPDATE: I had a mismatch in my PowerShell script in that I was running the replace on the wrong SQL script. The code above with an extra .Replace works like a charm
Long story short, I have an admin section where the user can choose from multiple dropdown lists the tables and fields that must be queries in order to get some values. Therefore, the query in ZEND is performed by concatenating the strings
$query = "SELECT $fieldName1, $fieldName2 from $tableName where $fieldName1 = $value";
How can I escape the above using ZEND approach to avoid sql injection? I tried adding them all as ? and calling quoteinto but it seems this does not work on some of the variables (like table names or field names)
ZF has quoteIdentifier() specifically for this purpose:
$query = "SELECT ".$db->quoteIdentifier($fieldName1).","...
In your case you might (also) want to check against a white list of valid column names.
Use quoteInto() or Zend_db_Select::where() for the values, and for the table and column names, I would simply strip any non alpha characters and then wrap them in ` quotes prior to using them in your SQL.
Example:
// Strip non alpha and quote
$fieldName1 = '`' . preg_replace('/[^A-Za-z]/', '', $fieldName1) . '`';
$tableName = '`' . preg_replace('/[^A-Za-z]/', '', $tableName) . '`';
// ....
// Build the SQL using Zend Db Select
$db->select()->from($tableName, array($fieldName1, $fieldName2))
->where($fieldName1 . ' = ?', $value);
In SafeMysql you can make it as simple, as
$sql = "SELECT ?n, ?n from ?n where ?n = ?s";
$data = $db->getAll($sql,$fieldName1,$fieldName2, $tableName, $fieldName1, $value);
though I understand that you won't change your ZF to SafeMysql.
Nevertheless, there is one essential thing that is ought to be done manually:
I doubt you want to let users to browse users table or financial table or whatever.
So, you have to verify a passed table name against an allowed tables array.
like
$allowed = ('test1','test2');
if (!in_array($tableName, $allowed)) {
throw new _403();
}
In a Zend_Db_Select object, I am doing a join to get user information for some data records. For the join is on a userId, I would like to combine the user first and last name into a single column of name.
Basically I am looking to have something similar to this:
$table = array('u' => 'User');
$condition = 'u.id = t.id';
$columns = array('UserName' => 'u.FirstName + " " + u.LastName')
$select->joinLeft($table, $condition, $columns);
I have tried using a Zend_Db_Expr with no luck and the above does not work.
How would I go about doing this?
Zend_Db_Expr is the way to go, but you'll have better luck if you use the database's concatenation function. Assuming MySQL:
$columns = new Zend_Db_Expr("CONCAT(u.FirstName, ' ', u.LastName') AS name")
I'm trying to use fetchAll on a query that has 2 variables. I can't figure out the syntax.
I can manage with only 1 variable:
$sql = "SELECT * FROM mytable WHERE field1 = ?";
$this->_db->fetchAll($sql,$value1); # that works
However I'm having some issues when query has multiple variables
$sql = "SELECT * FROM mytable WHERE field1 = ? AND field2 = ?";
$this->_db->fetchAll($sql,$value1,$value2); # doesn't work
$this->_db->fetchAll($sql,array("field1"=>$value1,"field2"=>$value2)); # doesn't work either
The reason why I want to use ? instead of placing the variables directly into the query is that I've learned that using ? allows for the query to be compiled generically by the db engine and improves performances.
There are two types of parameter, named parameters and positional parameters. You're mixing the two types and that won't work.
Named parameters match a placeholder by name. Names are started with the : symbol. The parameter names are not the same as the names of the columns you happen to use them for. You supply parameter values in an associative array, using the parameter name (not the column name) as the array keys. For example:
$sql = "SELECT * FROM mytable WHERE field1 = :param1 AND field2 = :param2";
$this->_db->fetchAll($sql,array("param1"=>$value1,"param2"=>$value2));
Positional parameters use the ? symbol for the placeholder. You supply parameter values using a simple (non-associative) array, and the order of values in the array must match the order of parameter placeholders in your query. For example:
$sql = "SELECT * FROM mytable WHERE field1 = ? AND field2 = ?";
$this->_db->fetchAll($sql,array($value1,$value2));
Most brands of SQL database natively support only one style or the other, but PDO attempts to support both, by rewriting the SQL if necessary before preparing the query. Since Zend_Db is modeled after PDO, Zend_Db also supports both parameter styles.
This question is a bit old, but I thought I'd just add to it for reference sake.
I would recommend starting to use Zend_Db_Select with Zend_Db. I've been doing a lot with Zend_Db lately. More from Zend_Db_Select reference guide.
Lets assume you have a Zend_Db adapter: $this->_db
# this will get the Zend_Db_Select object
$select = $this->_db->select();
# now you build up your query with Zend_Db_Select functions
$select->from('mytable');
$select->where('field1 = ?', $field1);
$select->where('field2 = ?', $field2);
[...]
# echo to see the SQL (helps in debugging)
# SELECT * FROM mytable WHERE field1 = ? AND field2 = ? [...]
echo '<p>My SQL: ' . $select . '</p>';
# Execute the SQL / Fetch results
$results = $select->query()->fetchAll();
That's the basics from your given example, but the Zend Framework reference guide on the select object has a lot of good information on how to build even more complex queries with JOINS, UNIONS, GROUP BY, LIMIT, HAVING, etc.
If you wanted to use an alias name for a table or parameters, you use an associative array with the alias name being the index value:
# SELECT p.* FROM products AS p
$select->from('p' => 'products');
If you want to return only selected fields, you add an array of field names as a second parameter:
# SELECT model FROM products
$select->from(products, array(model));
Actually, the above could should produce fully qualified SQL as:
SELECT 'products'.model FROM 'products'
but I wrote the above for brevity and clarity in the example.
One thing I just came across is using AND and OR in the WHERE condition.
# WHERE a = $a
$select->where('a = ?', $a);
# WHERE a = $a AND b = $b
$select->where('a = ?', $a);
$select->where('b = ?', $b);
# WHERE a = $a OR b = $b
$select->where('a = ?', $a);
$select->orWhere('b = ?', $b);
# WHERE a = $a AND b = $b
$select->orWhere('a = ?', $a);
$select->where('b = ?', $b);
Notice, that whatever the following "where" function you use, will combine with the previous statement as that operand. Ok, that sounded confusing.
If the second "where" is an "OR" it will be an "OR" conditional. If the second "where" is a "AND" the statement will be "AND".
In other words, the first WHERE function is ignored in terms of what condition it will use.
In fact, I just asked a question on Stack Overflow yesterday regarding doing a complex WHERE using select.
Hope that helps!
Cheers!
Try this:
$sql = "SELECT * FROM mytable WHERE field1 = ? AND field2 = ?";
$statement = $this->_db->query($sql,array("field1"=>$value1,"field2"=>$value2));
$data = $statement->fetchAll();
$this->_db must be an instance of Db adapter.
Heres the actual Zend way to code for this.
$sql = "SELECT * FROM mytable WHERE field1 = :param1 AND field2 = :param2";
$this->_db->fetchAll($sql,array("param1"=>$value1,"param2"=>$value2));
$where = $this->_db->select()
->from('mytable')
->where('field1 = ?',$value1)
->where('field2 = ?',$value2);
$rowSet = $this->_db->fetchAll($where);
This works great for me