Error while trying to test if a specific table exists in a MySQL database using JDBC

Question

I want to check wether a table named basestation exists in a MySQL table from a Java program using JDBC. My code is:

conn = DriverManager.getConnection(url, username, password);

DatabaseMetaData dbm = conn.getMetaData();

tables = dbm.getTables(null, null, "basestations", null);

if (tables.next())
{   
     //Table exists in database
     //...
}
else
{
     //Table does not exist
     //...
}

but although table basestations exists in my database it seems that my code never enters the first clause and always decides that table does not exist, causing naturally a table already exists in database SQL error when trying to create the table from the beginning.

Answer 1

Not the best way to do it below.. But you could do the following:

Use JDBC to send the following statement:

select count(*) from information_schema.tables where information_schema.table_schema='your_schema' and information_schema.table_name='basestations';

Parse the jdbc result set.

That should return either 1 or 0. If the resulting count is 1, then the table exists, otherwise, it does not.

Answer 2

I suspect your getTables() not returning anything here. As per getTables documentation Only table descriptions matching the catalog, schema, table name and type criteria are returned. In your case catalog and schema are null, which may not be correct (my guess), populate them with proper values.