Java – How to i solve PostgreSQL JDBC org.postgresql.util.PSQLException Error:

javajdbcpostgresqlsql

I've got problem with PostgreSQL JDBC

I use postgresql-9 and Glassfish if i execute the query with pgAdmin I don't have any error but in my application i have this error:

SEVERE: org.postgresql.util.PSQLException: ERREUR: erreur de syntaxe sur ou près de « d »
Position : 293
at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2103)
at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1836)
at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:257)
at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:512)
at org.postgresql.jdbc2.AbstractJdbc2Statement.executeWithFlags(AbstractJdbc2Statement.java:388)
at org.postgresql.jdbc2.AbstractJdbc2Statement.executeQuery(AbstractJdbc2Statement.java:273)

This is my java code

PreparedStatement st = con.prepareStatement("SELECT d.refdossier, d.status, d.date_validation, d.date_last_update,"
                        + "d.id_dossier,d.contrat_signe, d.etat_avancement,c.nom_pre_cont, c.num_piece_id,  c.date_piece_id,"
                        + "c.lieu_piece_id,  c.dat_nai_con, c.tel_con, fax_con,  c.email_con,g.libellegouvernoratar ,del.libelledelegationar"
                        + "FROM dossier d JOIN contact c on c.id_contact=d.id_dossier JOIN gouvernorat "
                        + " g on g.codegouvernorat=c.gouv JOIN delegation del on del.codedelegation=c.delegation"
                        + " WHERE d.id_dossier="+84);

res = st.executeQuery();

Best Answer

You are missing a space between del.libelledelegationar and FROM. This is causing the query to be parsed as:

SELECT ...., del.libelledelegationarFROM dossier d ....

In other words it sees a column del.libelledelegationarFROM with alias dossier and when the parser then sees d it trips, because it either expects a , or FROM, so it returns an error that there is a syntax error near d.

Related Solutions

Java – How to create a memory leak in Java

Here's a good way to create a true memory leak (objects inaccessible by running code but still stored in memory) in pure Java:

The application creates a long-running thread (or use a thread pool to leak even faster).
The thread loads a class via an (optionally custom) ClassLoader.
The class allocates a large chunk of memory (e.g. new byte[1000000]), stores a strong reference to it in a static field, and then stores a reference to itself in a ThreadLocal. Allocating the extra memory is optional (leaking the class instance is enough), but it will make the leak work that much faster.
The application clears all references to the custom class or the ClassLoader it was loaded from.
Repeat.

Due to the way ThreadLocal is implemented in Oracle's JDK, this creates a memory leak:

Each Thread has a private field threadLocals, which actually stores the thread-local values.
Each key in this map is a weak reference to a ThreadLocal object, so after that ThreadLocal object is garbage-collected, its entry is removed from the map.
But each value is a strong reference, so when a value (directly or indirectly) points to the ThreadLocal object that is its key, that object will neither be garbage-collected nor removed from the map as long as the thread lives.

In this example, the chain of strong references looks like this:

Thread object → threadLocals map → instance of example class → example class → static ThreadLocal field → ThreadLocal object.

(The ClassLoader doesn't really play a role in creating the leak, it just makes the leak worse because of this additional reference chain: example class → ClassLoader → all the classes it has loaded. It was even worse in many JVM implementations, especially prior to Java 7, because classes and ClassLoaders were allocated straight into permgen and were never garbage-collected at all.)

A variation on this pattern is why application containers (like Tomcat) can leak memory like a sieve if you frequently redeploy applications which happen to use ThreadLocals that in some way point back to themselves. This can happen for a number of subtle reasons and is often hard to debug and/or fix.

Update: Since lots of people keep asking for it, here's some example code that shows this behavior in action.

Java – Postgres with Java I can’t insert data

Your table is called TEST2 not test2. Apparently you created it using double quotes, which makes Postgres (and other standard-compliant DBMS) case-sensitive.

Because of that you now have to enclose the table in name in double quotes each time you refer to it.

String stm = "INSERT INTO \"TEST2\"(ID) VALUES(?)";

Most probably this is not what you intended, so just re-recreate the table without using double quotes around the identifiers:

CREATE TABLE test2
(
  ...
)

create a different table than:

CREATE TABLE "test2"
(
  ...
)

If you do not want to re-create the tables, you can rename them:

alter table "TEST2" rename to test2;

Best Answer

Related Solutions

Java – How to create a memory leak in Java

Java – Postgres with Java I can’t insert data

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