How can I execute non-query Stored Procedure in JDBC - java

I have a stored procedure in a postgres database. I'm using the postgres JDBC driver to execute a stored procedure, and I do not care about the return type, and can't execute the query. It's indicating that there's a syntax error near the name of the function.
In procedures that return rows, I've been able to do this via a PreparedStatement and setting the parameters, like:
PreparedStatement prepared = connection.prepareStatement("SELECT * FROM NonQueryProcedure(?)");
prepared.setInt(1, 999);
// ....
ResulSet resultSet = prepared.executeQuery();
However, I can't seem to get this to work for an "update" stored procedure where I don't care about the return type. I've tried using connection.prepareStatement() and prepareCall(), and also tried executing it with statement.execute(), .executeUpdate(), and .executeQuery(), without success.
How can I execute a stored procedure where I don't care about the return type?

As PostgreSQL has no "real" procedures, functions are simply executed using a SELECT statement:
statement.execute("select NonQueryProcedure(?)");
Note that inside a PL/pgSQL function, you can use the perform statement to call such a function. But this is not available outside of a PL/pgSQL block.

Without the actual syntax error, I can't say for sure, but try this:
"SELECT * FROM \"getData\"(?)"
CamelCase/PascalCase is a BAD idea in any SQL database. Either it folds it to a single case and all you see is AMASSOFUNREADABLELETTERS or it requires quoting and you will have to forevermore type "aMassofLettersAndQuotesAndShiftKeysAndMyFingersHurt" anytime you want to avoid a syntax error.

Related

"x is a procedure, use "call"" when I am already using call

I'm using Postgres 12 and have written this procedure:
CREATE OR REPLACE PROCEDURE reduceStock(id INTEGER, soldQuantity INTEGER)
LANGUAGE plpgsql AS
$$
BEGIN
UPDATE inventory SET ProductStockAmount = ProductStockAmount - soldQuantity WHERE ProductID = id;
END;
$$;
It works perfectly if I open up psql on the command line and run call reduceStock(1,1);
However, calling it from my Java program as follows:
CallableStatement stmt = conn.prepareCall("{call reduceStock(?, ?)}");
stmt.setInt(1, productID);
stmt.setInt(2, quantity);
stmt.execute();
Gives me the following error:
What I've Tried
running call reduceStock(1,1); from the psql client - works perfectly
dropping the database and starting over to see if some old definition was cached - didn't work
different capitalisations, spacings of call
Any ideas would be appreciated
You need to remove the curly braces, which are the JDBC escape for calling a procedure. But because Postgres has it's own call command, they are not needed (and collides with the JDBC escape).
CallableStatement stmt = conn.prepareCall("call reducestock(?, ?)");
The curly braces around the procedure inocation ({call reduceStock(?, ?)}) mean that this is not native SQL, but rather JDBC syntax. You can read more about it here: Why do JDBC calls to stored procedures wrap the call in curly brackets?.
So calls like this still have to get translated to the native SQL by the JDBC driver. It happens that the Postgres driver, by default, treats such statements as function calls and translates them to SELECT reduceStock(?, ?) SQL query. This is not how stored procedures shall be called in Postgres. In Postgres a stored procedure call SQL is call reduceStock(?, ?).
One way to make it work would be, like #a_horse_with_no_name wrote in his answer, to remove the curly braces. This makes the statement a native call and because it's a valid Postgres SQL this is going to work. The downside is that it makes it less cross-platform as it will not work for DBs that don't support the call procname() syntax. For example this won't work for Oracle, so if you have to support multiple JDBC drivers, this is the less-preferable way to go.
A better fix would be to hint Postgres JDBC driver to treat this syntax like a stored procedure call rather than a function call and translate it to SQL accordingly. For this purpose the Postgres driver exposes a escapeSyntaxCallMode configuration property (check out the EscapeSyntaxCallMode enum as well):
Specifies how the driver transforms JDBC escape call syntax into underlying SQL, for invoking procedures or functions. (backend >= 11) In escapeSyntaxCallMode=select mode (the default), the driver always uses a SELECT statement (allowing function invocation only). In escapeSyntaxCallMode=callIfNoReturn mode, the driver uses a CALL statement (allowing procedure invocation) if there is no return parameter specified, otherwise the driver uses a SELECT statement. In escapeSyntaxCallMode=call mode, the driver always uses a CALL statement (allowing procedure invocation only).
As you can see all {call something()} statements are treated like function calls by default and always translated to SELECTs. Setting escapeSyntaxCallMode to call will make the driver translate them to call SQL statements instead. The callIfNoReturn option seems most reasonable for most use-cases as it will transform JDBC calls to stored procedure calls if no return parameter has been specified and as function calls otherwise.
You can find an example of using this setting in Postgres docs (Chapter 6. Calling Stored Functions and Procedures):
// set up a connection
String url = "jdbc:postgresql://localhost/test";
Properties props = new Properties();
// ... other properties ...
// Ensure EscapeSyntaxCallmode property set to support procedures if no return value
props.setProperty("escapeSyntaxCallMode", "callIfNoReturn");
Connection con = DriverManager.getConnection(url, props);
// Setup procedure to call.
Statement stmt = con.createStatement();
stmt.execute("CREATE TEMP TABLE temp_val ( some_val bigint )");
stmt.execute("CREATE OR REPLACE PROCEDURE commitproc(a INOUT bigint) AS '"
+ " BEGIN "
+ " INSERT INTO temp_val values(a); "
+ " COMMIT; "
+ " END;' LANGUAGE plpgsql");
stmt.close();
// As of v11, we must be outside a transaction for procedures with transactions to work.
con.setAutoCommit(true);
// Procedure call with transaction
CallableStatement proc = con.prepareCall("{call commitproc( ? )}");
proc.setInt(1, 100);
proc.execute(); proc.close();>
-- https://jdbc.postgresql.org/documentation/head/callproc.html#call-procedure-example

issue while executing Sybase procedure from JDBC

While executing Sybase procedure from JDBC, I am getting below error:
Execute cursor is declared on a procedure which contains a non-SELECT
or a SELECT with COMPUTE clause. for the declaration of this cursor to
be legal it should have a single select statement without a compute
clause
I am using JCONN4 sybase jar. Does sybase has such restrictions on procedure to not have select statement with compute clause?
Also I searched in Sybase documentation but couldn't get proper answer.
http://infocenter.sybase.com/help/index.jsp?topic=/com.sybase.39996_1250/html/svrtsg/svrtsg348.htm
I cannot post the procedure here, but I can post the sample
create proc sample (#value_date datetime = null) as
begin
if #value_date is null
select #value_date = some_column from some_table
select a,b,c,d into #ad
from
table_a where a='something'
select a,b,c,d case when a=0 then 0 else b/a
from #ad
end
The above procedure is called using sybStatemt.executeQuery function
Looks like its Sybase bug. steps to reproduce the issue
Create a procedure having select with compute clause as i described above
write jdbc program and use belew method
statement.setFetchSize(1000);
Execute the program and you will see the error
now the question is does Sybase really has these kind of restrictions or it is specific to their Driver only and we can say its driver issue ?
You must use CallableStatement when calling store procedure
If you execute a stored procedure in a CallableStatement object that represents parameter values as question marks, you get better performance than if you use both question marks and literal values for parameters. Also, if you mix literals and question marks, you cannot use output parameters with a stored procedure.
The following example creates sp_stmt as a CallableStatement object for executing the stored procedure MyProc:
CallableStatement sp_stmt = conn.prepareCall( "{call MyProc(?,?)}");
The two parameters in MyProc are represented as question marks. You can register one or both of them as output parameters using the registerOutParameter methods in the CallableStatement interface.
In the following example, sp_stmt2 is a CallableStatement object for executing the stored procedure MyProc2.
CallableStatement sp_stmt2 = conn.prepareCall( {"call MyProc2(?,'javelin')}");
Run your sp from sybase command prompt.
If it gives result it should work with sybase driver.
I have used ado.net driver in c# it can run similar queries
https://marketplace.visualstudio.com/items?itemName=CDATASOFTWARE.SybaseADONETProvider
Your Sp looks simple. But i think your sp had some runtime issue.
I think this line
if #value_date is null
select #value_date = some_column from some_table
should be
if #value_date is null
select #value_date = some_column from some_table where col1='kkk' so that only
one value comes

java call oracle procedure with %rowtype parameter

I have been given an oracle procedure with the in out parameter %rowtype,like:
CREATE OR REPLACE PROCEDURE cleansing(
io_user IN OUT USER%rowtype
)
IS
BEGIN
--some pl/sql code
END cleansing;
USER is a table with more than 100 columns, I want to call the procedure by Java.
I can't change the procedure, because they are already used by other project.
I can't add procedure to database, because I don't have the permission to do it.
I google it, but can't find a good way to handle this.
what I want to do is:
1. pass the parameter.
2. get the parameter. some java demo code:
String sql = "{call cleansing(?)}";
try {
dbConnection = getDBConnection();
callableStatement = dbConnection.prepareCall(sql);
callableStatement.setXXX()//I don't know
callableStatement.registerOUTParameter(1, //I don't know the type.);
can anyone help me and give some demo code? no change to database and in out parameter mapping with java
This is possible but it's not really straightforward. You have to create something of type USER%ROWTYPE at runtime and use that to call your stored procedure. Take a look here for details.
To get output values as well, you have to do something extra, along the line of Sumit's comment. Basically, after your procedure call, you open a cursor that selects the relevant data from the USER parameter.
So you get a database statement as follows (pseudocode):
string sql =
"declare
user_param user%rowtype;
begin
-- Set necessary parameters
user_param.col0 := :p0In;
user_param.col1 := :p1In;
...
-- Call procedure.
cleansing(io_user => user_param);
-- Read necessary output values into cursor.
open :pOut for select user_param.col99 as col99
user_param.col98 as col98
...
from dual;
end;"
You call this entire statement the usual way, but you register a cursor out parameter (unfortunately, Java is a very long time ago for me so I'm not sure on the exact syntax).
callableStatement.registerOutParameter("pOut", OracleTypes.CURSOR);
...
callableStatement.execute();
...
ResultSet rs = (ResultSet) callableStatement.getObject("pOut");
// Read from result set.
EDIT: I turned this into a blogpost. Code examples are in C# but the idea is the same.

Can stored procedures return a result set?

I have a table named employee, which has his id, name, phone number. I am using MySQL as my database. I am using Java Swing for that. I am searching the employee table with name now using Java (I have used like clause in my Java page).
Now I need to implement that function in stored procedures. Is it possible? And how can we take that resultset in Java code, if it is possible??
Now I have written my stored procedure as follows
BEGIN
SELECT * FROM employee where empName like '%su%'
END
Sample code will be appreciated..
Thanks
First thing is you should write msql procedure that sends parameter for LIKE,
CREATE PROCEDURE simpleproc (param1 CHAR(20))
BEGIN
SELECT * FROM employee where empName like param1;
END
Then from java program you can use this code to use procedure,
CallableStatement cstmt = con.prepareCall("{call simpleproc(?)}");
cstmt.setString(1, "%su%");
ResultSet rs = cstmt.executeQuery();
When executing a stored procedure it may actually return multiple ResultSet objects and/or update counts if it does several statements.
You use CallableStatement to execute the proc and then getResultSet() or getUpdateCount() to get the right result. For multiple results sets/statements you call getMoreResults() to move through the results of the stored proc.
For a simple case like this you should just need to call getResultSet() once and process it.
Yes you can. A stored procedure can even return multiple resultsets.
DELIMITER $$ -- recognized by mysql client but not phpmyadmin
CREATE PROCEDURE prc_test()
BEGIN
SELECT *
FROM employee
WHERE empName LIKE '%su%';
END;
$$
DELIMITER ;
CALL prc_test(); -- to call

JDBC call to a synonym to Microsoft SQL Server stored procedure

Using the JDBC driver provided by Microsoft (sqljdbc4.jar) I am unable to call a stored procedure using a synonym defined for it.
I.e. for a synonym defined as:
CREATE SYNONYM dbo.synonym_name for dbo.procedure_name
when running the callable statement created by:
CallableStatement callStmt = conn.prepareCall("{ call [dbo].[synonym_name] (?,?,?,?,?,?) }");
I get an exception:
Exception in thread "main" com.microsoft.sqlserver.jdbc.SQLServerException: Parameter param_name was not defined for stored procedure [dbo].[synonym_name].
at com.microsoft.sqlserver.jdbc.SQLServerException.makeFromDriverError(SQLServerException.java:171)
at com.microsoft.sqlserver.jdbc.SQLServerCallableStatement.findColumn(SQLServerCallableStatement.java:1217)
at com.microsoft.sqlserver.jdbc.SQLServerCallableStatement.setString(SQLServerCallableStatement.java:1563)
at testmssql.main(testmssql.java:53)
Even though the parameters are correctly set (if I call the procedure directly (bypassing the synonym) everything works fine).
Further more, if I replace Microsoft's driver with JTDS, everything works fine.
How can one run a CallableStatement using a synonym for a stored procedure with Microsoft SQL Server's JDBC driver?
SQL Server Synonyms do not have query-able metadata. Judging by the error, JDBC is trying to confirm that the parameters declared in the Java code match the parameters declared on the stored procedure. That fails because of the missing metadata.
The only way around this is to create a passthrough stored procedure instead of the synonym.
So if you have this procedure:
CREATE PROCEDURE dbo.RealProcedure
#p1 INT,
#p2 INT
AS
BEGIN
RAISERROR('TODO: implement me',16,10);
END
And you have this synonym:
CREATE SYNONYM dbo.myProcedure FOR dbo.realProcedure;
Drop the synonym and create this procedure instead:
CREATE PROCEDURE dbo.myProcedure
#p1 INT,
#p2 INT
AS
BEGIN
EXEC dbo.realProcedure #p1,#p2;
END
There is a similar issue described here: http://social.msdn.microsoft.com/Forums/en-us/sqldataaccess/thread/dcdfee17-a926-4b57-8641-ed86fec989f2

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