mybatis plus time judgment problem

Mybatis plus time judgment

  <where>
            <if test="startTime != null">
                and eventtimestamp &gt;= #{startTime,jdbcType=TIMESTAMP}
            </if>
            <if test="endTime != null">
                and eventtimestamp &lt; #{endTime} ,INTERVAL 1 DAY)
            </if>
        </where>

Method 1: Escape using xml native escape#

• Character name    sql symbol    escaped characters
• greater than the number    >    >
• Less than the number     <    &lt;
• Not equal to     <>    &lt;&gt;
• Sign greater than or equal to/>=   &gt;=
• Sign less than or equal to     <=     &lt;=
• with
• Single quotes    '   &apos;
• Double quotes    "    &quot;

<if test="startTime != null and endTime != null">
                and change_time between #{startTime,jdbcType=TIMESTAMP} and #{endTime,jdbcType=TIMESTAMP}
            </if>

How to compare time and dates in mybatis plus

When obtaining records in the database that are equal to the current date, the eq method is still called, so the entity class includes the type in the database, which is Date, not DateTime, otherwise it can only obtain data at the same time.

pulbic void main(){
	LocalDate now = ();
	LambdaQueryWrapper<Ebbinghaus> queryWrapper = new LambdaQueryWrapper();
	(,now);
    (queryWrapper);
}

Mybatis-Plus time comparison is based on database functions, not string comparisons. In Mybatis-Plus, you can use the Wrapper object'sge、gt、le、ltMethod to compare time.

These methods will generate corresponding SQL statements according to the different databases to implement time comparison operations. So, there is no need to convert time to string for comparison.

If you want to compare the number of days, it is best to use LocalDate as the type of data instead of LocalDateTime, otherwise the comparison is only greater than the current moment, greater than or equal to the current moment.

If there is an operational requirement for the time value of the data, the following settings can be made:

@JsonFormat(pattern = "yyyy-MM-dd")
private LocalDateTime createTime;

The corresponding field type in the database is set to date, not datetime, so that the number of days can be compared and more abundant operations can be made at the moment.

Summarize

The above is personal experience. I hope you can give you a reference and I hope you can support me more.