在我目前的项目中,我正在使用sql CE.由于它不支持存储过程,我必须在存储库中编写SQL查询.
选项1:
StringBuilder query = new StringBuilder(); query.Append("SELECT"); query.Append(" c.CUSTOMER_ID,"); query.Append(" COALESCE (c.FirsT_NAME,'') + ' ' + COALESCE (c.LAST_NAME,'') AS FULL_NAME"); query.Append(" ct.NAME as CUSTOMER_TYPE"); query.Append("FROM "); query.Append(" CT_CUSTOMER_TYPE AS ct INNER JOIN CUSTOMER AS c ON ct.CUSTOMER_TYPE_ID = c.CUSTOMER_TYPE_ID");
选项2:
string query = "SELECT c.CUSTOMER_ID,COALESCE (c.FirsT_NAME,'') AS FULL_NAME,ct.NAME as CUSTOMER_TYPE FROM CT_CUSTOMER_TYPE AS ct INNER JOIN CUSTOMER AS c ON ct.CUSTOMER_TYPE_ID = c.CUSTOMER_TYPE_ID";
解决方法
选项2可能会快几纳秒,但是当您在数据库中添加实际执行的时间(几毫秒)时,几个额外的纳秒几乎不会记录为噪声.
在任何情况下,还有另一种选择,这是两个世界中最好的选择:@ -strings:
string query = @" SELECT c.CUSTOMER_ID,''_ + ' ' + COALESCE (c.LAST_NAME,'') AS FULL_NAME ct.NAME as CUSTOMER_TYPE FROM CT_CUSTOMER_TYPE AS ct INNER JOIN CUSTOMER AS c ON ct.CUSTOMER_TYPE_ID = c.CUSTOMER_TYPE_ID ";
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