Develop Reference

SQL Query fails in Java but works outside

I have a simple SQL query. It works fine if I use it in SequelPro but when I try to use the query in a Java statement if fails.
The query is operating on a simple table that only has two fields, idpolari and word. I originally structured the query as SELECT * FROM polari when this did not work I tried naming the specific fields. Have tried executing the query in SequelPro and against the database and it works fine. It also works from the command line. Just not working in Java.
I am working in Netbeans running MySQL on an IMac.
sql = "SELECT idpolari, word FROM polari";
Statement stmt = con.createStatement();
ResultSet res1 = stmt.executeQuery(sql);
I would have expected the full contents fo the polari table, what I get is this error message:
INFO: You have an error in your SQL syntax; check the manual that
corresponds to your MySQL server version for the right syntax to use
near '' at line 1 SELECT idpolari, word FROM polari

MariaDB JDBC chokes on column name containing curly brackets

I have a very simple SQL query I need to run
SELECT `id`, `{Document id}` FROM `test`.`test` LIMIT 10;
where {Document id} is a column name. Whenever I run it through MariaDB JDBC, it fails with error unknown escape sequence. From my understanding {CALL ...} is used to call stored procedure with a JDBC CallableStatement.
How do I escape it? I want JDBC to treat it as literal string without special meaning. \ didn't work for me.
As mentioned in deleted answer by #a_horse_with_no_name, there is setEscapeProcessing. But it's not supported by a lot of connectors (example MariaDB).

I have confirmed this issue using mariadb-java-client-2.2.5. It is not an issue with mysql-connector-java-5.1.44 so you might want to report this issue to MariaDB.
Following the suggestion by #JoopEggen in the comments above, I got it to work with MariaDB JDBC by adding sessionVariables=sql_mode=ANSI_QUOTES to the connection string and using
ResultSet rs = st.executeQuery("SELECT \"{Document id}\" FROM test.test");

Alter PostgreSQL sequence using Hibernate native sql query

My problem seems to be very simple but I have hard time resolving it.
I want to alter an PostgreSQL sequence using Hibernate via native sql query (other solutions are also welcomed) using next code:
Query query = getSession()
.createSQLQuery("ALTER SEQUENCE users_id_seq RESTART WITH ?")
.setInteger(0, 1);
query.executeUpdate();
But I am getting this error:
Hibernate:
ALTER SEQUENCE users_id_seq RESTART WITH ?
hibernate.engine.jdbc.spi.SqlExceptionHelper - SQL Error: 0, SQLState: 42601
hibernate.engine.jdbc.spi.SqlExceptionHelper - ERROR: syntax error at or near "$1"

Best I'm aware, you cannot prepare that statement.
If hibernate allows it, emulate the prepared statement, instead of sending it to the server. If not, sanitize the variable and issue the final statement directly.
Alternatively, wrap it in a function with dynamic SQL:
http://www.postgresql.org/docs/current/static/plpgsql-statements.html#PLPGSQL-STATEMENTS-EXECUTING-DYN

A query works in SQL*Plus but fails in JDBC with an ORA-00911 exception

I'm trying to track the amount of redo being generated during a database session with the following query:
SELECT a.name, b.VALUE
FROM v$statname a, v$mystat b
WHERE a.statistic# = b.statistic# AND a.name = 'redo size';
This query works directly in SQL*Plus and Toad, but I get an ORA-00911 exception using JDBC, and I've narrowed it down to the "statistic#" column name.
How do I get around this?

The column name statistic# is not the problem.
My bet is that you also send the terminating ; from inside your Java program.
But you may not include the the ; when executing a SQL statement through JDBC (at least not in Oracle and some other DBMS).
Remove the ; from your SQL String and it should be fine.

put it in double quotes - that should let you call a field anything in Oracle

Switch on JDBC logging, check your driver documentation for how to do this. In the JDBC log you see the actual statement prepared and executed in the DB. This eliminates one possible cause for the error.

SQL query works in phpmyadmin but not when using jdbc and java

This query works when I input it through phpmyadmin.
INSERT INTO conversation (user_id) VALUES (?);
INSERT INTO conversation (conversation_id, user_id)
VALUES ((SELECT LAST_INSERT_ID()), ?)
However when I send that query using jdbc and java I get an error -
You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'INSERT INTO conversation (conversation_id, user_id) VALUES ((SELECT LAST_INSERT_' at line 1"
I am using the exact same query. I checked by calling toString on the PreparedStatement and copying and pasting it into phpmyadmin and executing it and it worked fine. It just doesn't work through java. Any ideas whats wrong?

By default, you cannot execute multiple statements in one query through JDBC. Splitting it into two calls will work, as will changing the allowMultiQueries configuration property to True.
JDBC Configuration Properties — allowMultiQueries:
Allow the use of ';' to delimit multiple queries during one statement (true/false), defaults to 'false', and does not affect the addBatch() and executeBatch() methods, which instead rely on rewriteBatchStatements.
Default value: false