nlv函数

package io.trino.plugin.kdc.scalar;

import io.airlift.slice.Slice;
import io.trino.spi.function.Description;
import io.trino.spi.function.ScalarFunction;
import io.trino.spi.function.SqlNullable;
import io.trino.spi.function.SqlType;
import io.trino.spi.function.TypeParameter;

@Description("Return default value if the value is NULL else return value")
@ScalarFunction("nvl")
public final class HiveNvl
{
    private HiveNvl() {}

    @TypeParameter("T")
    @SqlType("T")
    @SqlNullable
    public static Slice nvlSlice(@SqlNullable @SqlType("T") Slice value, @SqlNullable @SqlType("T") Slice defaultValue)
    {
        return (value == null) ? defaultValue : value;
    }

    @TypeParameter("T")
    @SqlType("T")
    @SqlNullable
    public static Long nvlSlice(@SqlNullable @SqlType("T") Long value, @SqlNullable @SqlType("T") Long defaultValue)
    {
        return (value == null) ? defaultValue : value;
    }

    @TypeParameter("T")
    @SqlType("T")
    @SqlNullable
    public static Double nvlSlice(@SqlNullable @SqlType("T") Double value, @SqlNullable @SqlType("T") Double defaultValue)
    {
        return (value == null) ? defaultValue : value;
    }

    @TypeParameter("T")
    @SqlType("T")
    @SqlNullable
    public static Boolean nvlSlice(@SqlNullable @SqlType("T") Boolean value, @SqlNullable @SqlType("T") Boolean defaultValue)
    {
        return (value == null) ? defaultValue : value;
    }

    @TypeParameter("T")
    @SqlType("T")
    @SqlNullable
    public static Object nvlSlice(@SqlNullable @SqlType("T") Object value, @SqlNullable @SqlType("T") Object defaultValue)
    {
        return (value == null) ? defaultValue : value;
    }
}