PL/SQL Stored Procedures
Oracle JDBC drivers support execution of PL/SQL stored procedures and anonymous blocks. They support both SQL92 escape syntax and Oracle PL/SQL block syntax. The following PL/SQL calls would work with any Oracle JDBC driver:
// SQL92 syntax
CallableStatement cs1 = conn.prepareCall
( "{call proc (?,?)}" ) ; // stored proc
CallableStatement cs2 = conn.prepareCall
( "{? = call func (?,?)}" ) ; // stored func
// Oracle PL/SQL block syntax
CallableStatement cs3 = conn.prepareCall
( "begin proc (?,?); end;" ) ; // stored proc
CallableStatement cs4 = conn.prepareCall
( "begin ? := func(?,?); end;" ) ; // stored func
As an example of using Oracle syntax, here is a PL/SQL code snippet that creates a stored function. The PL/SQL function gets a character sequence and concatenates a suffix to it:
create or replace function foo (val1 char) return char as begin return val1 || 'suffix'; end;Your invocation call in your JDBC program should look like:
Connection conn = DriverManager.getConnection
("jdbc:oracle:oci:@", "scott", "tiger");
CallableStatement cs = conn.prepareCall ("begin ? := foo(?); end;");
cs.registerOutParameter(1,Types.CHAR);
cs.setString(2, "aa");
cs.executeUpdate();
String result = cs.getString(1);
Calling PL SQL from Java
JDBC and SQLJ allow you to call PL/SQL stored functions and procedures. For example, suppose you want to call the following stored function, which returns the balance of a specified bank account:
FUNCTION balance (acct_id NUMBER) RETURN NUMBER IS
acct_bal NUMBER;
BEGIN
SELECT bal INTO acct_bal FROM accts
WHERE acct_no = acct_id;
RETURN acct_bal;
END;
From a JDBC program, your call to the function balance might look like this:CallableStatement cstmt = conn.prepareCall("{? = CALL balance(?)}");
cstmt.registerOutParameter(1, Types.FLOAT);
cstmt.setInt(2, acctNo);
cstmt.executeUpdate();
float acctBal = cstmt.getFloat(1);
Calling a Stored Procedure in a Database
This example demonstrates how to call stored procedures with IN, OUT, and IN/OUT parameters.CallableStatement cs;
try {
// Call a procedure with no parameters
cs = connection.prepareCall("{call myproc}");
cs.execute();
// Call a procedure with one IN parameter
cs = connection.prepareCall("{call myprocin(?)}");
// Set the value for the IN parameter
cs.setString(1, "a string");
// Execute the stored procedure
cs.execute();
// Call a procedure with one OUT parameter
cs = connection.prepareCall("{call myprocout(?)}");
// Register the type of the OUT parameter
cs.registerOutParameter(1, Types.VARCHAR);
// Execute the stored procedure and retrieve the OUT value
cs.execute();
String outParam = cs.getString(1); // OUT parameter
// Call a procedure with one IN/OUT parameter
cs = connection.prepareCall("{call myprocinout(?)}");
// Register the type of the IN/OUT parameter
cs.registerOutParameter(1, Types.VARCHAR);
// Set the value for the IN/OUT parameter
cs.setString(1, "a string");
// Execute the stored procedure and retrieve the IN/OUT value
cs.execute();
outParam = cs.getString(1); // OUT parameter
} catch (SQLException e) {
}