I have a package that includes a T-SQL step. I have created som variables to use in the t-sql statement. But I don't find the correct syntax for using the variable in my t-sql statement.
My variable is QuarterID. And in my t-sql I want to use this variable.
t-sql:
DECLARE #myQuarterId int
select #myQuarterId = User::QuarterID
I have tried "#(User::QuarterID)", "#QuarterID", and all different syntax. Is there anyone out there who could help me on this one?
YOu open the Execute SQL task and got to the parameter mapping tab and add the variables inteh order you want to reference them. Make sure to change the parameter names to numbers starting with 0 for the first variable you use and incrementing by one for each other variable. Then go back to the general tab and write your query
DECLARE #myQuarterId int select #myQuarterId =?
Related
First off this is my first attempt at a multi select. I've done a lot of searching but I can't find the answer that works for me.
I have a postgresql query which has bg.revision_key in (_revision_key) which holds the parameter. A side note, we've named all our parameters in the queries with the underscore and they all work, they are single select in SSRS.
In my SSRS report I have a parameter called Revision Key Segment which is the multi select parameter. I've ticked Allow multi value and in Available Values I have value field pointing to revision_key in the dataset.
In my dataset parameter options I have Parameter Value [#revision_key]
In my shared dataset I also have my parameter set to Allow multi value.
For some reason I can't seem to get the multi select to work so I must be missing something somewhere but I've ran out of ideas.
Unlike with SQL Server, when you connect to a database using an ODBC connection, the parameter support is different. You cannot use named parameters and instead have to use the ? syntax.
In order to accommodate multiple values you can concatenate them into a single string and use a like statement to search them. However, this is inefficient. Another approach is to use a function to split the values into an in-line table.
In PostgreSQL you can use an expression like this:
inner join (select CAST(regexp_split_to_table(?, ',') AS int) as filter) as my on my.filter = key_column
Then in the dataset properties, under the parameters tab, use an expression like this to concatenate the values:
=Join(Parameters!Keys.Value, ",")
In other words, the report is concatenating the values into a comma-separated list. The database is splitting them into a table of integers then inner joining on the values.
I am pretty new to Pentaho so my query might sound very novice.
I have written a transformation in which am using CSV file input step and table input step.
Steps I followed:
Initially, I created a parameter in transformation properties. The
parameter birthdate doesn't have any default value set.
I have used this parameter in postgresql query in table input step
in the following manner:
select * from person where EXTRACT(YEAR FROM birthdate) > ${birthdate};
I am reading the CSV file using CSV file input step. How do I assign the birthdate value which is present in my CSV file to the parameter which I created in the transformation?
(OR)
Could you guide me the process of assigning the CSV field value directly to the SQL query used in the table input step without the use of a parameter?
TLDR;
I recommend using a "database join" step like in my third suggestion below.
See the last image for reference
First idea - Using Table Input as originally asked
Well, you don't need any parameter for that, unless you are going to provide the value for that parameter when asking the transformation to run. If you need to read data from a CSV you can do that with this approach.
First, read your CSV and make sure your rows are ok.
After that, use a select values to keep only the columns to be used as parameters.
In the table input, use a placeholder (?) to determine where to place the data and ask it to run for each row that it receives from the source step.
Just keep in ming that the order of columns received by the table input (the columns out of the select values) is the same order that it will be used for the placeholders (?). This should not be a problem with your question that uses only one placeholder, but keep that in mind as you ramp up using Pentaho.
Second idea, using a Database Lookup
This is another approach where you can't personalize the query made to the database and may experience a better performance because you can set a "Enable cache" flag and if you don't need to use a function on your where clause this is really recommended.
Third idea, using a Database Join
That is my recommended approach if you need a function on your where clause. It looks a lot like the Table Input approach but you can skip the select values step and select what columns to use, repeat the same column a bunch of times and enable a "outer join" flag that returns the rows without result from the query
ProTip: If you feel the transformation running too slow, try to use multiple copies from the step (documentation here) and obviously make sure the table have the appropriate indexes in place.
Yes there's a way of assigning directly without the use of parameter. Do as follows.
Use Block this step until steps finish to halt the table input step till csv input step completes.
Following is how you configure each step.
Note:
Postgres query should be select * from person where EXTRACT(YEAR
FROM birthdate) > ?::integer
Check Execute for each row and Replace variables in in Table input step.
Select only the birthday column in CSV input step.
I'm relatively new to DB2 for IBMi and am wondering the methods of how to properly cleanse data for a dynamically generated query in PHP.
For example if writing a PHP class which handles all database interactions one would have to pass table names and such, some of which cannot be passed in using db2_bind_param(). Does db2_prepare() cleanse the structured query on its own? Or is it possible a malformed query can be "executed" within a db2_prepare() call? I know there is db2_execute() but the db is doing something in db2_prepare() and I'm not sure what (just syntax validation?).
I know if the passed values are in no way effected by the result of user input there shouldn't be much of an issue, but if one wanted to cleanse data before using it in a query (without using db2_prepare()/db2_execute()) what is the checklist for db2? The only thing I can find is to escape single quotes by prefixing them with another single quote. Is that really all there is to watch out for?
There is no magic "cleansing" happening when you call db2_prepare() -- it will simply attempt to compile the string you pass as a single SQL statement. If it is not a valid DB2 SQL statement, the error will be returned. Same with db2_exec(), only it will do in one call what db2_prepare() and db2_execute() do separately.
EDIT (to address further questions from the OP).
Execution of every SQL statement has three stages:
Compilation (or preparation), when the statement is parsed, syntactically and semantically analyzed, the user's privileges are determined, and the statement execution plan is created.
Parameter binding -- an optional step that is only necessary when the statement contains parameter markers. At this stage each parameter data type is verified to match what the statement text expects based on the preparation.
Execution proper, when the query plan generated at step 1 is performed by the database engine, optionally using the parameter (variable) values provided at step 2. The statement results, if any, are then returned to the client.
db2_prepare(), db2_bind_param(), and db2_execute() correspond to steps 1, 2 and 3 respectively. db2_exec() combines steps 1 and 3, skipping step 2 and assuming the absence of parameter markers.
Now, speaking about parameter safety, the binding step ensures that the supplied parameter values correspond to the expected data type constraints. For example, in the query containing something like ...WHERE MyIntCol = ?, if I attempt to bind a character value to that parameter it will generate an error.
If instead I were to use db2_exec() and compose a statement like so:
$stmt = "SELECT * FROM MyTab WHERE MyIntCol=" . $parm
I could easily pass something like "0 or 1=1" as the value of $parm, which would produce a perfectly valid SQL statement that only then will be successfully parsed, prepared and executed by db2_exec().
Hello all,
I want to execute the following procedure:
EXECUTE MYDB.dbo.MYPROCEDURE
#gender='male',
#status='single'
The status can be single, divorced or married.
I need to execute the procedure having all the males that are single and divorced.
Ho can I do that?
Thanks a lot
The best way to do this would be to change your stored procedure over to a table-value function. Then you could call it twice and UNION ALL the results to get one resultset. The other way to do it would be to just call the stored procedure twice and add the results together yourself.
Unless you are fine with getting two resultsets back (by executing the statement twice), you will need to make some sort of modification to your SQL statement.
That's just not possible unless you rewrite the procedure
This is not possible without changing the Procedure.
One option would be to set the value as singledivorced and have the following WHERE clause:
WHERE [status]=#status
OR (#status='singledivorced' AND ([status]='single' or [status]='divorced'))
I have some code which utilizes parameterized queries to prevent against injection, but I also need to be able to dynamically construct the query regardless of the structure of the table. What is the proper way to do this?
Here's an example, say I have a table with columns Name, Address, Telephone. I have a web page where I run Show Columns and populate a select drop-down with them as options.
Next, I have a textbox called Search. This textbox is used as the parameter.
Currently my code looks something like this:
result = pquery('SELECT * FROM contacts WHERE `' + escape(column) + '`=?', search);
I get an icky feeling from it though. The reason I'm using parameterized queries is to avoid using escape. Also, escape is likely not designed for escaping column names.
How can I make sure this works the way I intend?
Edit:
The reason I require dynamic queries is that the schema is user-configurable, and I will not be around to fix anything hard-coded.
Instead of passing the column names, just pass an identifier that you code will translate to a column name using a hardcoded table. This means you don't need to worry about malicious data being passed, since all the data is either translated legally, or is known to be invalid. Psudoish code:
#columns = qw/Name Address Telephone/;
if ($columns[$param]) {
$query = "select * from contacts where $columns[$param] = ?";
} else {
die "Invalid column!";
}
run_sql($query, $search);
The trick is to be confident in your escaping and validating routines. I use my own SQL escape function that is overloaded for literals of different types. Nowhere do I insert expressions (as opposed to quoted literal values) directly from user input.
Still, it can be done, I recommend a separate — and strict — function for validating the column name. Allow it to accept only a single identifier, something like
/^\w[\w\d_]*$/
You'll have to rely on assumptions you can make about your own column names.
I use ADO.NET and the use of SQL Commands and SQLParameters to those commands which take care of the Escape problem. So if you are in a Microsoft-tool environment as well, I can say that I use this very sucesfully to build dynamic SQL and yet protect my parameters
best of luck
Make the column based on the results of another query to a table that enumerates the possible schema values. In that second query you can hardcode the select to the column name that is used to define the schema. if no rows are returned then the entered column is invalid.
In standard SQL, you enclose delimited identifiers in double quotes. This means that:
SELECT * FROM "SomeTable" WHERE "SomeColumn" = ?
will select from a table called SomeTable with the shown capitalization (not a case-converted version of the name), and will apply a condition to a column called SomeColumn with the shown capitalization.
Of itself, that's not very helpful, but...if you can apply the escape() technique with double quotes to the names entered via your web form, then you can build up your query reasonably confidently.
Of course, you said you wanted to avoid using escape - and indeed you don't have to use it on the parameters where you provide the ? place-holders. But where you are putting user-provided data into the query, you need to protect yourself from malicious people.
Different DBMS have different ways of providing delimited identifiers. MS SQL Server, for instance, seems to use square brackets [SomeTable] instead of double quotes.
Column names in some databases can contain spaces, which mean you'd have to quote the column name, but if your database contains no such columns, just run the column name through a regular expression or some sort of check before splicing into the SQL:
if ( $column !~ /^\w+$/ ) {
die "Bad column name [$column]";
}