數據庫同步表數據利器，oracle+mybatis 一個sql控制所有表增刪改 ${xxx} 和 #{xxx}的區別

數據庫同步表數據利器，mybatis 一個sql控制所有表增刪改

在項目開發過程中，尤其是多系統項目集羣中，經常會遇到需要從一個數據庫同步n張表到另一個數據庫中的需求，還需要對這些表做監聽，在發現有修改的時候進行增量數據同步。

通常的方法是在接受數據庫對應的項目中寫接口供數據源項目調用，這也就意味着我們需要寫n張表的增刪改sql語句，一條一條的寫，估計會累死，好在mybatis足夠給力，可以通過動態參數實現一條sql控制多張表的操作。

sql如下：

insert id="insertPotenTable" parameterType="com.ztesoft.zop.common.appvo.PotenChange" useGeneratedKeys="false">
        insert into ${table_name}
            <foreach collection="parameterMap" index="key" item="value" separator="," open="(" close=")">
                ${key}
            </foreach>
        values
            <foreach collection="parameterMap" index="key" item="value" separator="," open="(" close=")">
                <choose>
                    <when test="key.endsWith('_time') or key.endsWith('_date')">
                        to_date(#{value},'yyyy-mm-dd hh24:mi:ss')
                    </when>
                    <otherwise>
                        #{value}
                    </otherwise>
                </choose>
            </foreach>
    </insert>
    <update id="updatePotenTable" parameterType="com.ztesoft.zop.common.appvo.PotenChange">
        update ${table_name}
        set
        <foreach collection="parameterMap" index="key" item="value" separator=",">
            ${key} = 
            <choose>
                <when test="key.endsWith('_time') or key.endsWith('_date')">
                    to_date(#{value},'yyyy-mm-dd hh24:mi:ss')
                </when>
                <otherwise>
                    #{value}
                </otherwise>
            </choose>
        </foreach>
        where ${main_key} = #{main_key_value}
    </update>
    <delete id="delPotenTable" parameterType="com.ztesoft.zop.common.appvo.PotenChange">
        delete from ${table_name}
        where ${main_key} = #{main_key_value}
    </delete>

其中${xxx} 和 #{xxx} 的區別在於 mybatis會將${xxx}中的值不做任何處理寫到sql中，一般用於表名或字段名。
比較驚喜的是mybatis的if判斷居然還支持 字符串.endsWith(“xxx”)，可以用來做比較特殊的字段傳值操作，如date之類的特殊數據類型。

另外所傳的數據爲json格式 示例如下：

{
    "rows": [{
        "sql_id": "5",
        "sql_type": "insert",
        "main_key_value": "c1082b67391f4c6cb7caaee984dcfeac",
        "main_key": "log_id",
        "table_name": "potential_customer_oper_log",
        "parameterMap": {
            "log_id": "c1082b67391f4c6cb7caaee984dcfeac",
            "cmut_id": "1",
            "insert_type": "1",
            "create_time": "2018-05-17 19:26:41",
            "sys_user_id": "19920511",
            "the_day": "20",
            "pote_cust_id": "56",
            "the_month": "5",
            "the_year": "2018",
            "the_week": "17",
            "history_status": "0-1"
        }
    }, {
        "sql_id": "8",
        "sql_type": "update",
        "main_key_value": "a7729d697de14398a388f850aa2ac66f",
        "main_key": "log_id",
        "table_name": "potential_customer_oper_log",
        "parameterMap": {
            "log_id": "a7729d697de14398a388f850aa2ac66f",
            "cmut_id": "1",
            "insert_type": "1",
            "create_time": "2018-05-19 16:56:56",
            "sys_user_id": "19911234",
            "the_day": "20",
            "pote_cust_id": "66",
            "the_month": "5",
            "the_year": "2018",
            "the_week": "19",
            "history_status": "0-1"
        }
    }, {
        "sql_id": "7",
        "sql_type": "insert",
        "main_key_value": "d7970dc013104223874baa5ebe8d965c",
        "main_key": "log_id",
        "table_name": "potential_customer_oper_log",
        "parameterMap": {
            "log_id": "d7970dc013104223874baa5ebe8d965c",
            "cmut_id": "1",
            "insert_type": "2",
            "create_time": "2018-05-19 17:45:27",
            "sys_user_id": "19920511",
            "the_day": "19",
            "pote_cust_id": "66",
            "the_month": "5",
            "the_year": "2018",
            "the_week": "20",
            "history_status": "1-2"
        }
    }, {
        "sql_id": "6",
        "sql_type": "delete",
        "main_key_value": "f7526bf3d95946adae5187e8fd739fb1",
        "main_key": "log_id",
        "table_name": "potential_customer_oper_log",
        "parameterMap": {
            "log_id": "f7526bf3d95946adae5187e8fd739fb1",
            "cmut_id": "1",
            "insert_type": "1",
            "create_time": "2018-05-19 17:01:23",
            "sys_user_id": "19920511",
            "the_day": "20",
            "pote_cust_id": "67",
            "the_month": "5",
            "the_year": "2018",
            "the_week": "19",
            "history_status": "0-1"
        }
    }],

}