SQL Code,该如何处理

SQL Code
表 hpx中有字段theksh，thexm，thetime。我想将所有的theksh字段前面加一个‘0’。我是新手，请大家多多指点，谢谢

[解决办法]
update hpx
set theksh = '0' + isnull(theksh,'')
[解决办法]
update hpx set theksh = '0' + cast(theksh as varchar(100))

[解决办法]
update hpx
set theksh = '0' +ltrim(theksh )