1. SQL Translation and Migration Guide
  2. API Reference for SQL Translation of JDBC Applications

8 API Reference for SQL Translation of JDBC Applications

Consider the APIs that are part of the oracle.jdbc package, specifically the elements of oracle.jdbc that assist in SQL translation. To successfully migrate JDBC applications, it is important to understand the translation properties, interfaces, and the error translation mechanisms.

See Also:

  • Complete documentation of the oracle.jdbc package in Oracle Database JDBC Java API Reference

Translation Properties

The translation properties are listed in Table 8-1

Table 8-1 Translation Properties

Property Description

sqlTranslationProfile

Specifies the name of the transaction profile

sqlErrorTranslationFile

Specifies the path of the SQL error translation file

sqlTranslationProfile

The property oracle.jdbc.sqlTranslationProfile specifies the name of the transaction profile.

Declaration

oracle.jdbc.sqlTranslationProfile

Constant

OracleConnection.CONNECTION_PROPERTY_SQL_TRANSLATON_PROFILE

The value of the constant is oracle.jdbc.sqlTranslationProfile. This is also the property name.

Property Value

The value is a string. There is no default value.

Remarks

The property sqlTranslationProfile can be set as either a system property or a connection property. The property is required to use SQL translation. If this property is set then all statements created by the connection have SQL translation enabled unless otherwise specified.

sqlErrorTranslationFile

The property oracle.jdbc.sqlErrorTranslationFile specifies the path of the SQL error translation file.

Declaration

oracle.jdbc.sqlErrorTranslationFile

Constant

Oracle.connection.CONNECTION_PROPERTY_SQL_ERROR_TRANSLATION_FILE.

Property Value

The value is a path name. It has no default value.

Exceptions

An error in establishing a connection results in a SQLException but without a valid connection. However the SQL error translation file path is available either as a system property or connection property and will be used to translate the error.

Remarks

This file is used only for translating errors which occur when connection establishment fails. Once the connection is established this file is bypassed and is not considered even if it contains the translation details for any error which occurs after the connection is established. The property sqlErrorTranslationFile can be either a system property or a connection property. The content of this file is used to translate Oracle SQLExceptions into foreign SQLExceptions when there is no valid connection.

OracleTranslatingConnection Interface

This interface is only implemented by a Connection object that supports SQL Translation. The main purpose of this interface is to get non-translating statements (including preparedStatement and CallableStatement) from a translating connection.

The public interface oracle.jdbc.OracleTranslatingConnection defines the factory methods for creating translating and non-translating Statement objects.

The OracleTranslatingConnection enumerations are listed in Table 8-2:

Table 8-2 OracleTranslatingConnection Enumeration

Name Description

SqlTranslationVersion

Provides the Keys to the map

The OracleTranslatingConnection methods are listed in Table 8-3:

Table 8-3 OracleTranslatingConnection Methods

Name Description

createStatement()

Creates a Statement object with option to translate or not translate SQL.

prepareCall()

Creates a CallableStatement object with option to translate or not translate SQL.

prepareStatement()

Creates a PreparedStatement object with option to translate or not translate SQL.

getSQLTranslationVersions()

Returns a map of all the translation versions of the query during SQL Translation.

SqlTranslationVersion

The SqlTranslationVersion enumerated values specify the keys to the getSQLTranslationVersions() method.

Syntax

  public enum SqlTranslationVersion {
    ORIGINAL_SQL,
    JDBC_MARKER_CONVERTED,
    TRANSLATED
  }

The following table lists all the SqlTranslationVersion enumeration values with a description of each enumerated value.

Member Name Description

ORIGINAL_SQL

Specifies the original vendor specific sql

 
JDBC_MARKER_CONVERTED

Specifies that JDBC parameter markers ('?') is replaced with Oracle style parameter markers (':b<n>'). Hence consecutive '?'s will be converted to :b1, :b2, :b3 and so on. This change is required to take care of any changes in the order of parameters during translation. This version is sent to the server for translation. Hence any custom translations on the server must be registered from this version and not the ORIGINAL_SQL version. 

TRANSLATED

Specifies the translated query returned from the server

createStatement()

This group of methods create a Statement object, and specify whether the statement supports SQL translation. If the value of parameter translating is TRUE, then the returning statement supports translation and is identical to the corresponding version in the java.sql.Connection interface without the translating argument. If the value is FALSE, then the returning statement does not support translation.

Syntax Description 
public Statement createStatement(
  boolean translating)
throws SQLException;

Creates a Statement object with option to translate or not translate SQL. 

public Statement createStatement(
  int resultSetType,  int resultSetConcurrency,  boolean translating)
throws SQLException;

Creates a Statement object with the given type and concurrency with option to translate or not translate SQL. 

public Statement createStatement(
  int resultSetType,
  int resultSetConcurrency,
  int resultSetHoldability,
  boolean translating)
throws SQLException;

Creates a Statement object with the given type, concurrency, and holdability with option to translate or not translate SQL.

Parameters

Parameter Description 
resultSetType

Specifies the int value representing the result set type. 

resultSetConcurrency

Specifies the int value representing the result set concurrency type.

resultSetHoldability

Specifies the int value representing the result set holdability type. 

translating

Specifies whether or not the statement supports translation.

Return Value

The createStatement() method returns a Statement object.

Exceptions

The createStatement() method throws SQLException.

Example

Import the following packages before running the example:

import java.sql.*;
import java.util.Properties;
 
import oracle.jdbc.OracleConnection;
import oracle.jdbc.OracleTranslatingConnection;
import oracle.jdbc.pool.OracleDataSource;

Run the following SQL statements:

conn system/manager;
grant create sql translation profile to HR;
 
conn username/pwd;
drop table sample_tab;
create table sample_tab (c1 number, c2 varchar2(100));
insert into sample_tab values (1, 'A');
insert into sample_tab values (2, 'B');
commit;
exec dbms_sql_translator.drop_profile('FOO');
exec  dbms_sql_translator.create_profile('FOO');
exec  dbms_sql_translator.register_sql_translation('FOO','select row of (c1, c2) from sample_tab','select c1, c2 from sample_tab');

Example 8-1 Using the createStatement() method

public class SQLTransStmt 
{
  static String url="jdbc:oracle:thin:@localhost:5521:orcl";
  static String user="username", pwd="pwd";  
  static String PROFILE = "FOO";
  static String primitiveSql = "select row of (c1, c2) from sample_tab";
  
  public static void main(String[] args) throws Exception
  {       
    OracleDataSource ods = new OracleDataSource();
    ods.setURL(url);
        
    Properties props = new Properties();
    props.put("user", user);
    props.put("password", pwd);
    props.put(OracleConnection.CONNECTION_PROPERTY_SQL_TRANSLATION_PROFILE, PROFILE);
    ods.setConnectionProperties(props);
    Connection conn = ods.getConnection();
    System.out.println("connection for SQL translation: "+conn);
    
    try{
      OracleTranslatingConnection trConn = (OracleTranslatingConnection) conn;
      System.out.println("Call: oracle.jdbc.OracleTranslatingConnection.createStatement(true)");
      Statement trStmt = trConn.createStatement(true);
      System.out.println("executeQuery for: "+primitiveSql);
      ResultSet trRs = trStmt.executeQuery(primitiveSql);
      while (trRs.next())
        System.out.println("C1:"+trRs.getInt(1)+", C2:"+trRs.getString(2));
      trRs.close();
      trStmt.close();
    }catch (Exception e) {
      e.printStackTrace();
    }
    
    try{
      OracleTranslatingConnection trConn = (OracleTranslatingConnection) conn;
      System.out.println("Call: oracle.jdbc.OracleTranslatingConnection.createStatement(false)");
      Statement trStmt = trConn.createStatement(false);
      System.out.println("executeQuery for: "+primitiveSql);
      ResultSet trRs = trStmt.executeQuery(primitiveSql);
      while (trRs.next())
        System.out.println("C1:"+trRs.getInt(1)+", C2:"+trRs.getString(2));
      trRs.close();
      trStmt.close();
    }catch (Exception e) {
      System.out.println("expected Exception: "+e.getMessage());
    }
    
    try{
      OracleTranslatingConnection trConn = (OracleTranslatingConnection) conn;
      System.out.println("Call: oracle.jdbc.OracleTranslatingConnection.
createStatement(ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_UPDATABLE, true)");
      Statement trStmt = trConn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_UPDATABLE, true);
      System.out.println("executeQuery for: "+primitiveSql);
      ResultSet trRs = trStmt.executeQuery(primitiveSql);
      while (trRs.next())
        System.out.println("C1:"+trRs.getInt(1)+", C2:"+trRs.getString(2));
      System.out.println("move resultset back to 2nd row...");
      trRs.absolute(2);
      while (trRs.next())
        System.out.println("C1:"+trRs.getInt(1)+", C2:"+trRs.getString(2));
      trRs.close();
      trStmt.close();
    }catch (Exception e) {
      e.printStackTrace();
    }
    
    try{
      conn.setAutoCommit(false);
      OracleTranslatingConnection trConn = (OracleTranslatingConnection) conn;
      System.out.println("Call: oracle.jdbc.OracleTranslatingConnection.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_UPDATABLE,
 ResultSet.HOLD_CURSORS_OVER_COMMIT, true)");
      Statement trStmt = trConn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_UPDATABLE, ResultSet.HOLD_CURSORS_OVER_COMMIT, true);
      System.out.println("executeQuery for: "+primitiveSql);
      ResultSet trRs = trStmt.executeQuery(primitiveSql);
      trRs.last();
      System.out.println("C1:"+trRs.getInt(1)+", C2:"+trRs.getString(2));
      trRs.updateString(2, "Hello");
      trRs.updateRow();
      conn.commit();
      System.out.println("accept the update and list all of the rows again...");
      trRs.beforeFirst();
      while (trRs.next())
        System.out.println("C1:"+trRs.getInt(1)+", C2:"+trRs.getString(2));
      trRs.close();
      trStmt.close();
    }catch (Exception e) {
      e.printStackTrace();
    }
    
    conn.close();
  }
}

prepareCall()

This group of methods create a CallableStatement object, and specify whether the statement supports SQL translation. If the value of parameter translating is TRUE, then the returning statement supports translation. If the value is FALSE, then the returning statement does not support translation.

Syntax Description 
public CallableStatement prepareCall(
  String sql,
  boolean translating)
throws SQLException;

Creates a CallableStatement object with option to translate or not translate SQL 

public CallableStatement prepareCall(
  String sql,
  int resultSetType,
  int resultSetConcurrency,
  boolean translating)
throws SQLException;

Creates a CallableStatement object with the given type and concurrency with option to translate or not translate SQL 

public CallableStatement prepareCall(
  String sql,
  int resultSetType,
  int resultSetConcurrency,
  int resultSetHoldability,
  boolean translating)
throws SQLException;

Creates a CallableStatement object with the given type, concurrency, and holdability with option to translate or not translate SQL

Parameters

Parameter Description

sql

Specifies the String SQL statement value to be sent to the database; may contain one or more parameters 

resultSetType

Specifies the int value representing the result set type 

resultSetConcurrency

Specifies the int value representing the result set concurrency type

resultSetHoldability

Specifies the int value representing the result set holdability type 

translating

Specifies whether or not the statement supports translation

Return Value

The prepareCall() method returns a CallableStatement object.

Exceptions

The prepareCall() method throws SQLException.

Example

Import the following packages before running the example:

import java.sql.*;
import java.util.Properties;
 
import oracle.jdbc.OracleConnection;
import oracle.jdbc.OracleTranslatingConnection;
import oracle.jdbc.pool.OracleDataSource;

Run the following SQL statements:

conn system/manager;
grant create sql translation profile to HR;
 
conn username/pwd;
 
create or replace procedure sample_proc (p_num number, p_vchar in out varchar2) AS 
begin 
    p_vchar := 'p_num'||p_num||',  p_vchar'||p_vchar;
end;
/
 
exec dbms_sql_translator.drop_profile('FOO');
exec  dbms_sql_translator.create_profile('FOO');
exec  dbms_sql_translator.register_sql_translation('FOO', 'exec sample_proc(:b1, :b2)', '{call sample_proc(:b1, :b2)}');

Example 8-2 Using the prepareCall() method

public class SQLTransCstmt 
{
  static String url="jdbc:oracle:thin:@localhost:5521:orcl";
  static String user="username", pwd="pwd";  
  static String PROFILE = "FOO";
  static String primitiveSql = "exec sample_proc(:b1, :b2)";
  
  public static void main(String[] args) throws Exception
  {       
    OracleDataSource ods = new OracleDataSource();
    ods.setURL(url);
        
    Properties props = new Properties();
    props.put("user", user);
    props.put("password", pwd);
    props.put(OracleConnection.CONNECTION_PROPERTY_SQL_TRANSLATION_PROFILE,
      PROFILE);
    ods.setConnectionProperties(props);
    Connection conn = ods.getConnection();
    System.out.println("connection for SQL translation: "+conn);
    
    try{
      OracleTranslatingConnection trConn = (OracleTranslatingConnection) conn;
      System.out.println(
        "Call: oracle.jdbc.OracleTranslatingConnection.prepareCall(sql, true)");
      CallableStatement trStmt = trConn.prepareCall(primitiveSql, true);
      trStmt.setInt("b1", 1);
      trStmt.setString("b2", "A");      
      trStmt.registerOutParameter("b2", Types.VARCHAR);
      System.out.println("execute for: "+primitiveSql);
      trStmt.execute();
      System.out.println("out param: "+trStmt.getString("b2"));
      
      trStmt.close();
    }catch (Exception e) {
      e.printStackTrace();
    }
    
    try{
      OracleTranslatingConnection trConn = (OracleTranslatingConnection) conn;
      System.out.println(
        "Call: oracle.jdbc.OracleTranslatingConnection.prepareCall(sql, false)");
      CallableStatement trStmt = trConn.prepareCall(primitiveSql, false);
      trStmt.setInt(1, 1);
      trStmt.setString(2, "A");     
      System.out.println("execute for: "+primitiveSql); 
      ResultSet trRs = trStmt.executeQuery();
      while (trRs.next())
        System.out.println("C1:"+trRs.getInt(1)+", C2:"+trRs.getString(2));
      trRs.close();
      
      trStmt.close();
    }catch (Exception e) {
      System.out.println("expected Exception: "+e.getMessage());
    }
    
    conn.close();
  }
}

prepareStatement()

This group of methods create a PreparedStatement object, and specify whether the statement supports SQL translation. If the value of parameter translating is TRUE, then the returning statement supports translation. If the value is FALSE, then the returning statement does not support translation.

Syntax Description 
public PreparedStatement prepareStatement(
  String sql,
  boolean translating)
throws SQLException;

Creates a PreparedStatement object with option to translate or not translate SQL 

public PreparedStatement prepareStatement(
  String sql,
  int resultSetType,
  int resultSetConcur,
  boolean translating)
throws SQLException;

Creates a PreparedStatement object with the given type and concurrency with option to translate or not translate SQL 

public PreparedStatement prepareStatement(
        String sql,
        int resultSetType,
        int resultSetConcur,
        int resultSetHold,
        boolean translating)
throws SQLException;

Creates a PreparedStatement object with the given type, concurrency, and holdability with option to translate or not translate SQL

Parameter Description

sql

Specifies the String SQL statement value to be sent to the database; may contain one or more parameters 

resultSetType

Specifies the int value representing the result set type 

resultSetConcur

Specifies the int value representing the result set concurrency type

resultSetHold

Specifies the int value representing the result set holdability type 

translating

Specifies whether or not the statement supports translation

Return Value

The prepareStatement() method returns a PreparedStatement object.

Usage Notes

When the "?" placeholder is used with the prepareStatement() method, the driver internally changes the "?" to Oracle-style parameters because the server side translator can only work with Oracle-style markers. This is necessary to distinguish the bind variables. If not, any change in the order of the bind variables will be indistinguishable. The replaced oracle style markers follow the format :b<n> where <n> is an incremental number. For example, exec sample_proc(?,?) becomes exec sample_proc(:b1,:b2).

To further exemplify, consider a scenario of a vendor format where the vendor query selecting top three rows is SELECT * FROM employees WHERE first_name=? AND employee_id=? TOP 3. The query has to be converted to oracle dialect. In this case the following translation is to be registered on the server:

From: 

SELECT * FROM employees WHERE first_name=:b1 AND employee_id=:b2 TOP 3

To: 

SELECT * FROM employees WHERE first_name=:b1 AND employee_id=:b2 AND ROWNUM <= 3

See SqlTranslationVersion and "SQL Translation of JDBC Applications" for more information.

Exceptions

The prepareStatement() method throws SQLException.

Example

Import the following packages before running the example:

import java.sql.*;
import java.util.Properties;
 
import oracle.jdbc.OracleConnection;
import oracle.jdbc.OracleTranslatingConnection;
import oracle.jdbc.pool.OracleDataSource;

Run the following SQL statements:

conn system/manager;
grant create sql translation profile to USER;
 
conn username/pwd;
drop table sample_tab;
create table sample_tab (c1 number, c2 varchar2(100));
insert into sample_tab values (1, 'A');
insert into sample_tab values (1, 'A');
insert into sample_tab values (1, 'A');
commit;
exec dbms_sql_translator.drop_profile('FOO');
exec  dbms_sql_translator.create_profile('FOO');
exec  dbms_sql_translator.register_sql_translation('FOO','select row of select c1, c2 from sample_tab
 where c1=:b1 and c2=:b2','select c1, c2 from sample_tab where c1=:b1 and c2=:b2');

Example 8-3 Using the prepareStatement() method

public class SQLTransPstmt 
{
  static String url="jdbc:oracle:thin:@localhost:5521:orcl";
  static String user="username", pwd="pwd";  
  static String PROFILE = "FOO";
  static String primitiveSql = "select row of select c1, c2 from sample_tab 
    where c1=:b1 and c2=:b2";
  
  public static void main(String[] args) throws Exception
  {       
    OracleDataSource ods = new OracleDataSource();
    ods.setURL(url);
        
    Properties props = new Properties();
    props.put("user", user);
    props.put("password", pwd);
    props.put(OracleConnection.CONNECTION_PROPERTY_SQL_TRANSLATION_PROFILE,
      PROFILE);
    ods.setConnectionProperties(props);
    Connection conn = ods.getConnection();
    System.out.println("connection for SQL translation: "+conn);
    
    try{
      OracleTranslatingConnection trConn = (OracleTranslatingConnection) conn;
      System.out.println("Call:
        oracle.jdbc.OracleTranslatingConnection.prepareStatement(sql, true)");
      PreparedStatement trStmt = trConn.prepareStatement(primitiveSql, true);
      trStmt.setInt(1, 1);
      trStmt.setString(2, "A");      
      System.out.println("executeQuery for: "+primitiveSql);
      ResultSet trRs = trStmt.executeQuery();
      while (trRs.next())
        System.out.println("C1:"+trRs.getInt(1)+", C2:"+trRs.getString(2));
        trRs.close();    
        trStmt.close();
      }catch (Exception e) {
      e.printStackTrace();
    }
    
    try{
      OracleTranslatingConnection trConn = (OracleTranslatingConnection) conn;
      System.out.println("Call:
        oracle.jdbc.OracleTranslatingConnection.prepareStatement(sql, false)");
      PreparedStatement trStmt = trConn.prepareStatement(primitiveSql, false);
      trStmt.setInt(1, 1);
      trStmt.setString(2, "A");    
      System.out.println("executeQuery for: "+primitiveSql);  
      ResultSet trRs = trStmt.executeQuery();
      while (trRs.next())
        System.out.println("C1:"+trRs.getInt(1)+", C2:"+trRs.getString(2));
      trRs.close();
      
      trStmt.close();
    }catch (Exception e) {
    System.out.println("expected Exception: "+e.getMessage());
    }
    
    try{
      OracleTranslatingConnection trConn = (OracleTranslatingConnection) conn;
      System.out.println("Call:
        oracle.jdbc.OracleTranslatingConnection.prepareStatement(
        sql, ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_UPDATABLE, true)");
      PreparedStatement trStmt = trConn.prepareStatement(
        primitiveSql, ResultSet.TYPE_SCROLL_SENSITIVE, 
        ResultSet.CONCUR_READ_ONLY, true);
      trStmt.setInt(1, 1);
      trStmt.setString(2, "A");
      System.out.println("executeQuery for: "+primitiveSql);
      ResultSet trRs = trStmt.executeQuery();
      while (trRs.next())
        System.out.println("C1:"+trRs.getInt(1)+", C2:"+trRs.getString(2));
            
      System.out.println("trRs.beforeFirst and show resultSet again...");
      trRs.beforeFirst();
      while (trRs.next())
        System.out.println("C1:"+trRs.getInt(1)+", C2:"+trRs.getString(2));
      trRs.close();
      trStmt.close();
    }catch (Exception e) {
    e.printStackTrace();
    }
    
  conn.close();
  }
}

getSQLTranslationVersions()

Returns a map of all the translation versions of the query during SQL Translation. In case of an exception, and if suppressExceptions is true, then the translated version in the map is NULL.

Syntax

public Map<SqlTranslationVersion, String> getSqlTranslationVersions(
  String sql, 
  boolean suppressExceptions) 
throws SQL Exception;

Return Value

Map with all translation versions of a query. See SqlTranslationVersion enum for more details about returning versions.

Exception

This method throws SQLException if there is a problem in query translation, provided suppressExceptions is false.

Error Translation Configuration File

An XML configuration file (path) is provided as a value of the oracle.jdbc.sqlErrorTranslationFile property. This file contains the translations information for errors. These errors occur when a connection to the server cannot be established and thus translation cannot happen on the server. Error messages are of the type that define the state of the database that prevents the connection from being established.

The structure of the configuration XML file is defined in the DTD as follows:

<!DOCTYPE LocalTranslationProfile[
 
<!ELEMENT LocalTranslationProfile (Exception+)>
<!ELEMENT Exception (ORAError, ErrorCode, SQLState )>
<!ELEMENT ORAError (#PCDATA)>
<!ELEMENT ErrorCode (#PCDATA)>
<!ELEMENT SQLState (#PCDATA)>
]>

where,

  • ORAError is an int value and specifies the error code for the oracle error.

  • ErrorCode is an int value and specifies the vendor error code, that is, the translated code.

  • SQLState is a String value and specifies the vendor SQL state.