Data Types

Data Type are the specific data type for a database collection field. While reading or inserting, there can be converted with DataType Adapters (Show below).

List of data types

DataType	Description
DOUBLE	Represent decimal numbers
DECIMAL	Represent decimal numbers
FLOAT	Represent decimal numbers
INTEGER	Represent numbers
LONG	Represent long numbers
CHAR	Represent short amount of characters
STRING	Represent a set of characters
LONG_TEXT	Represent a very long text, in most sql databases, the max size of the column would be multiple gb
DATE	Represent the java date
DATETIME	Represent the datetime
TIMESTAMP	Represent the sql timestamp, it can be got from timestamp long
BINARY	Represent all binary data
UUID	Represent uuid class in java, by default the uuid will be converted to binary
BOOLEAN	Represent boolean

DataType Adapter

A data type adapter convert a specific java class to another at inserting and converts it back by reading from the result.

Create an own adapter

In this example, the preregistered uuid type adapter is used. View the UUIDTypeAdapter example at github.

Write operation

The write method will be called by inserting, finding, deleting and updating a value.

@Override
public Object write(UUID value) {
    byte[] uuidBytes = new byte[16];
    ByteBuffer.wrap(uuidBytes)
            .order(ByteOrder.BIG_ENDIAN)
            .putLong(value.getMostSignificantBits())
            .putLong(value.getLeastSignificantBits());
    return uuidBytes;
}

Read operation

The read operation will be called by using the getObject(key/index, javaClass) method in QueryResultEntry. If there is no adapter registered for the class, an exception will be throwed.

@Override
public UUID read(Object value) {
    return Convert.toUUID(value);
}

Default data type adapters

By default, there are several data type adapters registered. On your choice, you can register and unregister all adapters at runtime.

Default adapters: - UUID - InetSocketAddress - InetAddress

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Last update: 2020-12-15