文件名称：在查询时尽量少用格式转换-ORACLE+SQL性能优化(全)
文件大小：2.32MB
文件格式：PPT
更新时间：2024-05-15 15:58:34
SQL
在查询时尽量少用格式转换 如用 WHERE a.order_no = b.order_no 不用 WHERE TO_NUMBER (substr(a.order_no, instr(b.order_no, '.') - 1) = TO_NUMBER (substr(a.order_no, instr(b.order_no, '.') - 1)