SQL语句的几个常用函数

Oracle：select substr(isdn,instr('86',isdn),length(isdn)) from tablename

Sybase：select substring(isdn,charindex('86',isdn),datalength(isdn)) from tablename

Oracle：select replace(isdn,'86','') from tablename

Sybase：select str_replace(isdn,'86','') from tablename //比如stuff()好用

以上几个粗体字所代表的关键字实现的功能以及参数都是一样的，但函数名称不一样，需要注意。

未完待续...

使用decode解决查询中的条件问题：

                        sql1.append(" and decode(substr(othermdn,1,");
                        sql1.append(GlobalConfig.COUNTRYCODE.length());
                        sql1.append("),");
                        sql1.append(DBAUtil.getSqlString(GlobalConfig.COUNTRYCODE));
                        sql1.append(",substr(othermdn,");
                        sql1.append(GlobalConfig.COUNTRYCODE.length() + 1);
                        sql1.append(",length(othermdn)),othermdn)=");
                        sql1.append(DBAUtil.getSqlString(mobile));

绕过交叉匹配的问题（特殊）
                        sql1.append(" and othermdn in(");
                        sql1.append(DBAUtil.getSqlString(DBAUtil.get86Mdn(mobile)));
                        sql1.append(",");
                        sql1.append(DBAUtil.getSqlString(DBAUtil.getMdn(mobile)));
                        sql1.append(")");