Crelate

Building the JDBC URL

After installing the license, access the connection management page by executing the command "java -jar kingswaysoft.jdbc.jar". Enter the necessary details, and the program will automatically generate the JDBC connection URL. Users can click Test Connection to test the generated URL and Copy to Clipboard to copy the connection string for use within the application where the JDBC driver is being used.

Note: If a license is not installed, you can still use the connection manager to generate a JDBC URL, but the 'Test Connection' feature will be disabled.

General Page

The General page allows you to specify connection properties and login credentials for the Crelate REST service:

General Settings

API Throttling Rate

The API Throttling Rate will limit the number of requests that can be sent per second. Set this value to 0 to disable API Throttling.

Authentication Methods for Crelate

Advanced Settings Page

Using the JDBC Driver

Explore detailed examples in this section that demonstrate the application of JDBC classes such as Connection, Statement, and ResultSet to effectively manage interactions with Crelate data. This section covers the use of regular statements and prepared statements for executing complex or frequently executed queries.

Executing Statements

Once you've connected from your code (see Connecting with DriverManager and Connecting with DataSource), you can execute SQL statements using the Statement class. Refer to the Executing Prepared Statements section for information on how to execute parameterized statements.

SELECT

Use the Statement class's generic execute method or the executeQuery method to execute SQL statements that return data. To retrieve the results of a query, you would then call the getResultSet method of the Statement.

String sql = "SELECT * FROM activities WHERE ids IN ('b5f7b8df-ae3c-487e-4210-b7acfe48dc08', 'ebf71795-4957-44f7-43b3-0c705844dc08')";
try {
    ResultSet resultSet = statement.executeQuery(sql);
    LOGGER.info(resultSet.toString());
} catch (SQLException e) {
    LOGGER.severe(e.toString());
}

INSERT

Use either the generic execute method or the executeUpdate method of the Statement class to execute an INSERT operation.

The results of SQL queries are saved in a ResultSet. You can retrieve the ResultSet after execution to view the inserted data's ID, exceptions raised during execution, and details of the affected data.

String sql = "INSERT INTO companies (Name, Description) VALUES ('nameInsert', 'Insert Description Text')";
try {
    statement.executeUpdate(sql);
    LOGGER.info(statement.getResultSet().toString());
} catch (SQLException e) {
    LOGGER.severe(e.toString());
}

id,errorcode,errormessage,processdata,haserrors
9592ec16-9d4a-4991-5d6f-78aa330edd08,null,null,{"entity":{"Name":"nameInsert","Description":"Insert Description Text"}},false

UPDATE

Use either the generic execute method or the executeUpdate method of the Statement class to execute an UPDATE operation.

The results of SQL queries are saved in a ResultSet. You can retrieve the ResultSet after execution to view the updated data's ID, exceptions raised during execution, and details of the affected data.

String sql = "UPDATE activities SET Display = 'nameUpdate' WHERE Id = 'c7f903d8-2d58-40c9-56a8-a8c61d0bdd08'";
try {
    statement.executeUpdate(sql);
    LOGGER.info(statement.getResultSet().toString());
} catch (SQLException e) {
    LOGGER.severe(e.toString());
}

id,errorcode,errormessage,processdata,haserrors
c7f903d8-2d58-40c9-56a8-a8c61d0bdd08,null,null,{"entity":{"Name":"nameUpdate"}},false

DELETE

Use either the generic execute method or the executeUpdate method of the Statement class to execute a DELETE operation.

Deleted records aren't deleted permanently from Crelate, but they are placed in the Recycle Bin for 15 days from where they can be restored.

The results of SQL queries are saved in a ResultSet. You can retrieve the ResultSet after execution to view the deleted data's ID, exceptions raised during execution, and details of the affected data.

String sql = "DELETE FROM activities WHERE Id = '7be93970-c7e3-4b40-2700-3d0a2a0edd08'";
try {
    statement.executeUpdate(sql);
    LOGGER.info(statement.getResultSet().toString());
} catch (SQLException e) {
    LOGGER.severe(e.toString());
}

id,errorcode,errormessage,processdata,haserrors
7be93970-c7e3-4b40-2700-3d0a2a0edd08,null,null,null,false

Executing Prepared Statements

Using a PreparedStatement can improve performance when you need to execute a SQL statement multiple times with different parameters. Unlike a Statement object, a PreparedStatement object is provided with a SQL statement when it is created, which can then be executed with different values each time. This special type of statement is derived from the more general class, Statement.

Below are the steps outlining how to execute a prepared statement:

1. Create a PreparedStatement: Use the prepareStatement method of the Connection class to instantiate a PreparedStatement. Refer to Connecting with DriverManager or Connecting with DataSource for information related to establishing connections.
2. Set Parameters: Declare parameters by calling the corresponding setter method of the PreparedStatement. Note: The parameter indices start at 1.
3. Execute the Statement: Use the generic execute or executeUpdate method of the PreparedStatement.
4. Retrieve Results: Call the getResultSet method of the Prepared Statement to obtain the query results, which will be returned as a ResultSet.
5. Iterate Over the Result Set: Use the next method of the ResultSet to iterate through the results. To obtain column information, utilize the ResultSetMetaData class. Instantiate a ResultSetMetaData object by calling the getMetaData method of the ResultSet.

SELECT

Use the Statement class's generic execute method or the executeQuery method to execute SQL statements that return data.

The results of SQL queries are saved in a ResultSet. You can retrieve the ResultSet after execution to view the retrieved data.

String sql = "SELECT * FROM companies WHERE names IN (?, ?)";
try {
    PreparedStatement ps = connection.prepareStatement(sql);
    ps.setString(1, "nameInsert");
    ps.setString(2, "nameUpdate");
    ps.execute(query);
    while (ps.getResultSet().next()) {
        for (int i = 1; i <= ps.getResultSet().getMetaData().getColumnCount(); i++) {
            LOGGER.info(ps.getResultSet().getMetaData().getColumnLabel(i) + "="
            + ps.getResultSet().getString(i));
        }
    }
} catch (SQLException e) {
    LOGGER.error(e);
}

INSERT

Use either the generic execute method or the executeUpdate method of the Statement class to execute an INSERT operation.

The results of SQL queries are saved in a ResultSet. Users can retrieve the ResultSet after execution to view the ID of inserted data, exceptions raised during execution, and the data affected by the insertion.

String sql = "INSERT INTO companies (Name, Description) VALUES (?, ?)";

try {
    PreparedStatement ps = connection.prepareStatement(sql);
	ps.setString(1, "nameInsert");
	ps.setString(2, "Insert Description Text");
    ps.executeUpdate();
    LOGGER.info(ps.getResultSet().toString());
} catch (SQLException e) {
    LOGGER.error(e);
}

id,errorcode,errormessage,processdata,haserrors
9592ec16-9d4a-4991-5d6f-78aa330edd08,null,null,{"entity":{"Name":"nameInsert","Description":"Insert Description Text"}},false

UPDATE

Use either the generic execute method or the executeUpdate method of the Statement class to execute an UPDATE operation.

The results of SQL queries are saved in a ResultSet. Users can retrieve the ResultSet after execution to view the ID of updated data, exceptions raised during execution, and the data affected by the update.

String sql = "UPDATE companies SET Name = ? WHERE Id = ?";
try {
    PreparedStatement ps = connection.prepareStatement(sql);
    ps.setString(1, "nameUpdate");
	ps.setString(2, "c7f903d8-2d58-40c9-56a8-a8c61d0bdd08");
    ps.executeUpdate();
    LOGGER.info(ps.getResultSet().toString());
} catch (SQLException e) {
    LOGGER.error(e);
}

id,errorcode,errormessage,processdata,haserrors
c7f903d8-2d58-40c9-56a8-a8c61d0bdd08,null,null,{"entity":{"Name":"nameUpdate"}},false

DELETE

Use either the generic execute method or the executeUpdate method of the Statement class to execute a DELETE operation.

After a record is deleted, it is placed in the Recycle Bin for 15 days, after which it will be unrestorable.

The results of SQL queries are saved in a ResultSet. You can retrieve the ResultSet after execution to view the deleted data's ID, exceptions raised during execution, and details of the affected data.

String sql = "DELETE FROM companies WHERE Id = ?";
try {
    PreparedStatement ps = connection.prepareStatement(sql);
	ps.setString(1, "7be93970-c7e3-4b40-2700-3d0a2a0edd08");
    ps.executeUpdate();
    LOGGER.info(ps.getResultSet().toString());
} catch (SQLException e) {
    LOGGER.error(e);
}

id,errorcode,errormessage,processdata,haserrors
7be93970-c7e3-4b40-2700-3d0a2a0edd08,null,null,null,false

Metadata Discovery

This section provides examples on how to retrieve table and column metadata using the getTables, getColumns, and getPrimaryKeys methods from the DatabaseMetaData interface. These are essential for discovering database structures.

Tables

The getTables method from the DatabaseMetaData interface can be used to retrieve a list of tables.

try {
    Connection connection = buildRestConnectionFromDriverManager();
    ResultSet rs = connection.getMetaData().getTables(null, null, null, null);
    LOGGER.info("\r\n" + rs.toString());
} catch (SQLException e) {
    LOGGER.severe(e.getMessage());
}

TABLE_CAT,TABLE_SCHEM,TABLE_NAME,TABLE_TYPE,REMARKS
null,null,activities,Table,
null,null,activitytypes,Table,
null,null,applications,Table,
......

The getTables method returns the following metadata columns:

Columns

Use the getColumns method of the DatabaseMetaData interface to retrieve detailed information about the columns in the database. To narrow your search to a specific table, specify the table name as a parameter.

try {
    Connection connection = buildRestConnectionFromDriverManager();
    ResultSet rs = connection.getMetaData().getColumns(null, null, "companies", null);
    LOGGER.info(rs.toString());
} catch (SQLException e) {
    e.printStackTrace();
}

TABLE_CAT,TABLE_SCHEM,TABLE_NAME,COLUMN_NAME,DATA_TYPE,TYPE_NAME,COLUMN_SIZE,BUFFER_LENGTH,DECIMAL_DIGITS,NUM_PREC_RADIX,NULLABLE,REMARKS,COLUMN_DEF,SQL_DATA_TYPE,SQL_DATETIME_SUB,CHAR_OCTET_LENGTH,ORDINAL_POSITION,IS_NULLABLE,IS_AUTOINCREMENT,IS_GENERATEDCOLUMN,DTS_TYPE
null,null,companies,AccountBalance,3,java.lang.Object,0,null,0,0,null,null,null,3,null,null,null,null,null,null,DT_DECIMAL
null,null,companies,AccountSourceId.EntityName,12,java.lang.String,255,null,0,0,null,null,null,12,null,null,null,null,null,null,DT_WSTR
null,null,companies,AccountSourceId.Id,12,java.lang.String,0,null,0,0,null,null,null,12,null,null,null,null,null,null,DT_GUID

The getColumns method returns the following columns:

Primary Keys

The getPrimaryKeys method in the DatabaseMetaData interface is used to retrieve metadata about primary keys for a given table in Crelate.

try {
    Connection connection = buildRestConnectionFromDriverManager();
    ResultSet resultSet = connection.getMetaData().getPrimaryKeys(null, null, "countries");
    LOGGER.info("\r\n" + resultSet.toString());
    Assertions.assertNotNull(resultSet);
} catch (SQLException e) {
    LOGGER.severe(e.getMessage());
}

TABLE_NAME,PRIMARY_COLUMN_NAME
countries,Id

The getPrimaryKeys method returns the following columns:

Connection Settings