目录1引言....................................................................................................................................................................11.11.21.31.42目的及范围........................................................................................................................................................1参考资料............................................................................................................................................................1定义....................................................................................................................................................................1文档结构............................................................................................................................................................1数据库基础........................................................................................................................................................12.12.22.32.4SQL概念.............................................................................................................................................................1SQL的组成.........................................................................................................................................................2OPENSQL.............................................................................................................................................................2NATIVESQL...........................................................................................................................................................23提取数据............................................................................................................................................................33.13.23.3SELECT语句........................................................................................................................................................3选择单行数据....................................................................................................................................................3选择多行数据....................................................................................................................................................53.3.13.3.23.3.33.43.4.13.4.23.4.33.4.43.4.53.4.63.4.73.53.5.13.5.23.5.33.5.43.63.6.13.6.23.6.3读取多行....................................................................................................................................................5多行选择——选择到内表.........................................................................................................................5指定包的大小............................................................................................................................................6比较运算符................................................................................................................................................6范围限定运算符号（BETWEEN）........................................................................................................6字符比较运算符........................................................................................................................................7检...
