The requirement is to generate a single report connecting to a single DB:
Query1 is a group by query and has a bar chart and pie chart based on it.
Query2 is a simple query on which a table gets created.
Both these queries need results based on a WHERE clause, which is supplied dynamically.
Can somebody point me to some examples on how to achieve this?
Thank you.
You can tell JasperReports to use a parameter to define part of the query using the $P!{PARAMETER_NAME} syntax. This tells JasperReports to use the literal value of PARAMETER_NAME as part of the query. You can then do:
Create a parameter named WHERE_CLAUSE in the report.
Give WHERE_CLAUSE a default value of 1=1.
Consider the following SQL statement:
SELECT * FROM table WHERE $P!{WHERE_CLAUSE}
The $P! expression changes the literal SQL statement to:
SELECT * FROM table WHERE 1=1
That is a valid query. Note the difference between $P{} and $P!{} -- the exclamation mark (!) is important.
You can then supply the SQL conditions dynamically.
Related
I have a Lookup that retrieves a few records from a MS SQL table containing schema, table name and a whole where clause. These values are passed to a copy data (within a ForEach) In the copy data i use a Dynamic query statement like:
#concat('select a.*, current_date as crt_tms from ',item().shm_nam,'.',item().tab_nam,
item().where_clause )
This construction works fine without the where_clause or with a where clause with an integer. But it goes wrong with strings like:
'a where a.CODSYSBRN ='XXX' ;'
it's about the quote (')
How can i pass it through?
I know that the where clause as a fixed string in the dynamic query works when i use double quotes (to escape the single quote):
'a where a.CODSYSBRN =''XXX'' ;'
Point is i need the where clause to be completely dynamic because it differ per table
whatever i try i get this kind of error:
Syntax error or access violation;257 sql syntax error: incorrect syntax near "where a"
ps i also tested this, but with the same result:
select a.*, current_date as crt_tms from #{item().shm_nam}.#{item().tab_nam} a #{item().where_clause}
As you have mentioned you are getting whole where clause from the lookup table, the query must have included the column values in where clause for string and integer types separately.
Example lookup table:
In your copy activity, you can use Concat() function as you were already doing it, to combine static values & parameters.
#concat('select * from ',item().schma_name,'.',item().table_name,' ',item().where_clause)
For debugging purposes, I have added the expression in set variable activity, to see the value of the expression.
Iteration1:
Iteration2:
I'm using a PostgreSQL with a Go driver. Sometimes I need to query not existing fields, just to check - maybe something exists in a DB. Before querying I can't tell whether that field exists. Example:
where size=10 or length=10
By default I get an error column "length" does not exist, however, the size column could exist and I could get some results.
Is it possible to handle such cases to return what is possible?
EDIT:
Yes, I could get all the existing columns first. But the initial queries can be rather complex and not created by me directly, I can only modify them.
That means the query can be simple like the previous example and can be much more complex like this:
WHERE size=10 OR (length=10 AND n='example') OR (c BETWEEN 1 and 5 AND p='Mars')
If missing columns are length and c - does that mean I have to parse the SQL, split it by OR (or other operators), check every part of the query, then remove any part with missing columns - and in the end to generate a new SQL query?
Any easier way?
I would try to check within information schema first
"select column_name from INFORMATION_SCHEMA.COLUMNS where table_name ='table_name';"
And then based on result do query
Why don't you get a list of columns that are in the table first? Like this
select column_name
from information_schema.columns
where table_name = 'table_name' and (column_name = 'size' or column_name = 'length');
The result will be the columns that exist.
There is no way to do what you want, except for constructing an SQL string from the list of available columns, which can be got by querying information_schema.columns.
SQL statements are parsed before they are executed, and there is no conditional compilation or no short-circuiting, so you get an error if a non-existing column is referenced.
I am trying to make workload test in Jmeter.
This is Postgresql and I would like to combine a random variable with '%'.
Could you help me the way to make sql query?
I have already tried with '?%', but there is an error "The column index is out of range: 1, number of columns: 0.".
The easiest way is switching to Select Statement and amend your query to look like:
SELECT * FROM scloud_usr.tcus_usr_rgn where UID like '${__RandomString(3,ABD,UID)}%'
If you want to continue with the Prepared Select Statement you need to add this % wildcard to the parameter value itself, not in the query, i.e.
More information:
Using “like” wildcard in prepared statement
Performance Testing BLOB from a MySQL Database with JMeter
Prepared statements with % wildcards
is it possible to refer to a column/table name by using a string? Something like SELECT * FROM 'my_table'::table_name_t?
The reason I'm asking: I have a table geometry_columns with some geometry tables. And I would like to know which objects are within a certain radius.
Thanks, Philip
You will need a (stored) function to achieve this. The function takes the table name as an argument, creates the SQL dynamically and then returns the result of the SELECT based on that query.
here are some examples (not exactly what you need, but they should get you headed in the right direction):
http://forums.devshed.com/postgresql-help-21/plpgsql-variable-representing-table-name-137201.html
Dynamic column in SELECT statement postgres
I don't think you can do that directly. I think you would have to build the select statement from another statement or piece of code, then execute the resulting statement.
I have a query which uses a cursor to cycle through the results of a select statement.
The select statement in short selects all of the records from a mapping table I have. One of the columns is 'SourceTableName'.
I use this field to generate some dynamic SQL.
I am looking to add a parameter to my stored procedure wrapped around this, which will allow me to only create dynamic SQL for the 'SourceTableName' that I want - IF I pass in a 'SourceTableNameFilter'.
I am stuck with some logic which wraps my dynamic SQL.
IF #SourceTableNameFilter(SP parameter) = #SourceTableName(from mapping table)
BEGIN
Generate and execute some dynamic SQL based on the SourceTableName.
The problem is, I want this to either work on all tables that come back from a select against 'SourceTableName' BUT if a #SourceTableNameFilter parameter is present and not null - then only generate dynamic SQL for any rows in the cursor which match my filter parameter.
Is there a way for me to accomplish this with an IF statement without copying the logic inside the IF/ELSE twice?
FETCH NEXT FROM TABLECUR INTO #SourceTableName
,#SourceInColumn
,#SourceOutColumn
,#TargetTableName
,#TargetLookupColumn
,#TargetLookupResultColumn
,#MappingTableID
WHILE (##fetch_status <> -1)
BEGIN
IF (##fetch_status <> -2)
BEGIN
IF (#SourceTableName = #SourceTableNameFilter)
--GENERATE DYNAMIC SQL
ELSE
--GENERATE DYNAMIC SQL FOR ALL RECORDS
The generate dynamic SQL string is the same in both the if and the else, any way to change the conditions so that I'm not duplicating the dynamic SQL generation and to not generate dynamic SQL when the #SourceTableName != #SourceTableNameFilter?
Thank you
Consider adding this logic to the cursor definition, rather than having that logic within the processing of each cursor record.
So if the cursor is normally:
DECLARE MY_CURSOR Cursor FOR
SELECT SourceTableName, SourceInColumn, SourceOutColumn
,TargetTableName, TargetLookupColumn
,TargetLookupResultColumn, MappingTableID
FROM MappingTable
--get source tables when filter is specified; otherwise get all
WHERE (SourceTableName = #SourceTableNameFilter) OR (LEN(ISNULL(SourceTableNameFilter,'')=0)
Now you can execute your business logic within the cursor without having to detect the filtered table or not. The cursor is loaded with the records you need to care about. It sounds, from the question, that the business logic is the same, no matter if the filter was passed in or not. If this is incorrect, or if it doesn't satisfy your requirement, please comment.
Knowing nothing about the dynamic sql you're building, I'd recommend doing something along the lines of:
SET #DynamicCommand = '<whatever, first part>'
+ isnull(#SourceTableNameFilter
,'<no special action, perhaps just empty string>'
,'<add conditional text dependent upon contents of #SourceTableNameFilter>')
+ '<whatever, second part>'