how to get list of Databases "Schema" names of MySql using java JDBC

Question

如何使用java JDBC获取MySql的数据库“架构”名称列表？

Answer 1

The getSchemas() method of the DatabaseMetaData is the obvious but with MySQL you have to use getCatalogs()

http://download.oracle.com/javase/7/docs/api/java/sql/DatabaseMetaData.html#getSchemas() http://download.oracle.com/javase/7/docs/api/java/sql/DatabaseMetaData.html#getCatalogs()

Example:

Class.forName("com.mysql.jdbc.Driver");

// change user and password as you need it
Connection con = DriverManager.getConnection (connectionURL, "user", "password");

ResultSet rs = con.getMetaData().getCatalogs();

while (rs.next()) {
    System.out.println("TABLE_CAT = " + rs.getString("TABLE_CAT") );
}

Answer 2

• Either use SHOW DATABASES to see if it is inside,
• Check the INFORMATION_SCHEMA,
• or just do USE DATABASE; and catch the error.

Answer 3

DatabaseMetaData meta = conn.getMetaData();
ResultSet schemas = meta.getSchemas();
while (schemas.next()) {
  String tableSchema = schemas.getString(1);    // "TABLE_SCHEM"
  String tableCatalog = schemas.getString(2); //"TABLE_CATALOG"
  System.out.println("tableSchema "+tableSchema);
}

Answer 4

DatabaseMetaData dbmd = con.getMetaData();
ResultSet ctlgs = dbmd.getCatalogs();
while(ctlgs.next())
{
System.out.println("ctlgs  =  "+ctlgs.getString(1));
}