Column Annotation

The @Column annotation is used to specify the mapping relationship between entity fields and database table columns.

Parameters

Parameter	Type	Default Value	Description
value	String	""	The name of the database column
ignore	Boolean	false	Whether to ignore this column when generating SQL
resultHandler	KClass<out ResultHandler>	ResultHandler::class	The result handler for this column
operator	ColumnOperator	ColumnOperator.EQUAL	SQL operator (such as EQUAL) can be used for condition entity

Usage Example

import com.tang.kite.annotation.Column;

public class User {

    private Long id;

    @Column("user_name")
    private String username;

    @Column(ignore = true)
    private String temporary;

    @Column(resultHandler = GenderResultHandler.class)
    private String gender;

    @Column(operator = ColumnOperator.LIKE)
    private String nickname;

}

Custom Result Handler

The ResultHandler interface allows to define custom result processing logic for special handling when query results are mapped to entity fields.

import com.tang.kite.result.ResultHandler;
import com.tang.kite.utils.Reflects;
import java.lang.reflect.Field;

public class GenderResultHandler implements ResultHandler {

    // Custom default value for null
    @Override
    public <T> void setNullValue(Field field, T instance) {
        Reflects.setValue(field, instance, "Not Specified");
    }

    @Override
    public <T> void setValue(Field field, T instance, Object value) {
        Reflects.setValue(field, instance, value);
    }

}

Setting SQL Operator

ColumnOperator enum defines common SQL operators, which can be specified through the operator parameter of the @Column annotation.

The default is EQUAL, which means using the equals operator.

# @Column(operator = ColumnOperator.LIKE)
where nickname like '%value%'

# @Column(operator = ColumnOperator.GT)
where age > value

# @Column(operator = ColumnOperator.IS_NULL)
where deleted_time is null