sql 和shell操作比较

SQL                                                                      Linux 命令 说明
WHERE col1 = 'value'                                           grep value   限制结果，返回匹配项
WHERE col1 != 'value'                                          grep -v value  限制结果，返回不匹配的项 
ORDER BY 1                                                          sort    按序排列结果
SELECT DISTINCT col1                                          uniq field1  从结果中删除重复项
SELECT COUNT(*) , col1 FROM y GROUP BY x       sort | uniq -c  找出在一组结果中存在多少给定结果
SELECT col2, col1                                                 awk '{print $2 "\t" $1}'  将结果限制为给定结果数据行的特定部分