from 1是指从变量的第一个字符起。就象SQLServer中的substring(@var,1,len(field1))
那如果?填充的是1331234,那是不是就是相当于要执行7个select语句? 即: select * from TableDef.IIP_NUMTABMOB where phonenum=1; select * from TableDef.IIP_NUMTABMOB where phonenum=13 select * from TableDef.IIP_NUMTABMOB where phonenum=133; ... select * from TableDef.IIP_NUMTABMOB where phonenum=1331234;
?='133123433333333334545', phonenum字段的长度为7的话 要执行的语句就是:select * from TableDef.IIP_NUMTABMOB where phonenum='1331234'.(只会执行这一句)
终于查到了,是Informix里的字符串函数, 语法是: substring(exp from begin for length); 谢谢楼上的朋友!
即:
select * from TableDef.IIP_NUMTABMOB where phonenum=1;
select * from TableDef.IIP_NUMTABMOB where phonenum=13
select * from TableDef.IIP_NUMTABMOB where phonenum=133;
...
select * from TableDef.IIP_NUMTABMOB where phonenum=1331234;
要执行的语句就是:select * from TableDef.IIP_NUMTABMOB where phonenum='1331234'.(只会执行这一句)
语法是:
substring(exp from begin for length);
谢谢楼上的朋友!