sql语句多条件查询语句拼接

经常遇到条件查询是多个条件一起查询，这样可以比较方便的把条件语句拼接在一起

sqlStr += " where 1=1 ";if(name!= "不选择"){sqlStr += " and name= '" + name+ "'";}else if(r1!= "不选择"){sqlStr += " and r1= '" + r1+ "'";}else if(dataType != "不选择"){sqlStr += " and DataType = '" + dataType + "'";}else if(fileType != "不选择"){sqlStr += " and FileType = '" + fileType + "'";}