PB9写的一个拆解SQL语句的通用函数

将以下内容复制，另存为 f_split_sql.srf 然后导入pbl中

 

1. $PBExportHeader$f_split_sql.srf 

$PBExportComments$SQL操作：分割SQL语句为select、from、where、group by、order by 5个子句 

global type f_split_sql from function_object 

end type 

 

forward prototypes 

global subroutine replace_n (ref string input_str,readonly string replaced_str,readonly string replace_str) 

global subroutine f_split_sql (string as_sql, ref string as_select, ref string as_from, ref string as_where, ref string as_group, ref string as_order) 

end prototypes 

 

global subroutine replace_n (ref string input_str,readonly string replaced_str,readonly string replace_str);string s1 

string s2 

long p 

long n 

 

p = 1 

 

do while 1 = 1 

    p = pos(input_str,replaced_str,p) 

 

    if p = 0 then 

        exit 

    end if 

 

    s1 = mid(input_str,1,p - 1) 

    s2 = mid(input_str,p + len(replaced_str)) 

    input_str = s1 + replace_str + s2 

    p = p + len(replace_str) 

loop 

end subroutine 

 

global subroutine f_split_sql (string as_sql, ref string as_select, ref string as_from, ref string as_where, ref string as_group, ref string as_order);//==================================================================== 

// 过程(函数|Function): f_split_sql() 

//-------------------------------------------------------------------- 

// 描述(Description): 拆解SQL语句 

//-------------------------------------------------------------------- 

// 变量(Arguments):  

//              string  as_sql      传入的SQL语句（如：select a from t where b = 1 group by c order by c） 

//      ref     string  as_select   拆解后的select语句（如：select a） 

//      ref     string  as_from     拆解后的from  语句（如：from t） 

//      ref     string  as_where    拆解后的where 语句（如：where b = 1）  

//      ref     string  as_group    拆解后的group 语句（如：group by c）   

//      ref     string  as_order    拆解后的order 语句（如：order by c）   

//-------------------------------------------------------------------- 

// 返回(Returns):  (none) 

//-------------------------------------------------------------------- 

// 作者(Author):  yyoinge     Date: 2012-02-17 13:26 

//-------------------------------------------------------------------- 

// 修改历史(Modify History):  

//   

//-------------------------------------------------------------------- 

as_sql = lower(trim(as_sql)) 

if as_sql = '' then return 

as_select = ''; as_from = ''; as_group = ''; as_order = '' 

 

replace_n(as_sql,'~r',' ')  

replace_n(as_sql,'~n',' ')  

replace_n(as_sql,'~r~n',' ')  

replace_n(as_sql,'~t',' ')  

replace_n(as_sql, '(select ',' ( select ') 

replace_n(as_sql, ',select ',' , select ') 

replace_n(as_sql,';','  ')  

if leftw(as_sql, 7) <> 'select ' then return 

long ll_gb_p, ll_ob_p, ll_fr_p, ll_se_p, ll_wh_p, ll_tmp, ll_yh_p 

int li_leap = 0 

//先剔除''内的内容,如：'abc'替换为@@@@@ 

string ls_sql 

ls_sql = as_sql 

do while true 

    ll_yh_p = posw(ls_sql, "'")  

    if ll_yh_p <= 0 then exit 

    ll_tmp = posw(ls_sql, "'", ll_yh_p + 1) 

    if ll_tmp <= 0 then return 

    ls_sql = leftw(ls_sql, ll_yh_p - 1) + fill('@', ll_tmp - ll_yh_p + 1) + midw(ls_sql, ll_tmp + 1)     

loop 

 

//********************************  select 

ll_tmp = 8 

li_leap = -1 

do while true 

    ll_fr_p = posw(ls_sql, " from ", ll_tmp) 

    ll_se_p = posw(ls_sql, " select ", ll_tmp) 

    if ll_fr_p <= 0 then return 

    if ll_fr_p < ll_se_p or ll_se_p = 0 then 

        li_leap ++ 

    else 

        li_leap -- 

    end if 

    if li_leap = 0 then 

        as_select = leftw(as_sql, ll_fr_p) 

        exit 

    end if 

    if ll_fr_p <= 0 then ll_fr_p = 999999 

    if ll_se_p <= 0 then ll_se_p = 999999 

    ll_tmp = min(ll_fr_p, ll_se_p) + 5 

loop 

 

if as_select = '' then return 

 

 

//********************************  group by 

ll_gb_p = lastpos(ls_sql, " group by ") 

ll_ob_p = lastpos(ls_sql, " order by ") 

if ll_gb_p > 0 then 

    if posw(ls_sql, " from ", ll_gb_p + 1) > 0 or posw(ls_sql, " where ", ll_gb_p + 1) > 0 then 

        as_group = '' 

        ll_gb_p = 0 

    else 

        if ll_ob_p > ll_gb_p then 

            as_group = midw(as_sql, ll_gb_p, ll_ob_p - ll_gb_p) 

        else 

            as_group = midw(as_sql, ll_gb_p) 

        end if 

    end if 

else 

    as_group = '' 

end if 

 

//********************************  order by 

if ll_ob_p > 0 then 

    if posw(ls_sql, " from ", ll_ob_p + 1) > 0 or posw(ls_sql, " where ", ll_ob_p + 1) > 0 then 

        as_order = '' 

        ll_ob_p = 0 

    else 

        as_order = midw(as_sql, ll_ob_p) 

    end if 

else 

    as_order = '' 

end if 

//取得select from where 语句的最后一个字符的位置+1 

if ll_gb_p <= 0 then ll_gb_p = ll_ob_p 

if ll_gb_p <= 0 then ll_gb_p = lenw(as_sql) + 1 

 

//********************************  where 

as_sql = midw(leftw(as_sql,ll_gb_p - 1), ll_fr_p) 

ls_sql = midw(leftw(ls_sql,ll_gb_p - 1), ll_fr_p) 

ll_wh_p = lastpos(ls_sql, " where ") 

if ll_wh_p <= 0 then 

    as_where = '' 

else 

    ll_tmp = 5 

    li_leap = 0 

    do while true 

        ll_se_p = posw(ls_sql, "(", ll_tmp) 

        ll_fr_p = posw(ls_sql, ")", ll_tmp) 

        if ll_se_p > ll_wh_p then ll_se_p = 0 

        if ll_fr_p > ll_wh_p then ll_fr_p = 0 

        if (ll_se_p = 0 and ll_fr_p = 0) then exit 

        if ll_fr_p < ll_se_p or ll_se_p = 0 then 

            li_leap ++ 

        else 

            li_leap -- 

        end if 

        if ll_fr_p <= 0 then ll_fr_p = 999999 

        if ll_se_p <= 0 then ll_se_p = 999999 

        ll_tmp = min(ll_fr_p, ll_se_p) + 1 

    loop 

    if li_leap <> 0 then 

        as_where = '' 

    else 

        as_where = midw(as_sql, ll_wh_p) 

        as_sql = leftw(as_sql, ll_wh_p) 

    end if 

end if 

 

//********************************  from 

as_from = as_sql 

 

end subroutine 

 

调用时，这样写：

 

string ls_sql, ls_select, ls_from, ls_where, ls_group, ls_order 

 

ls_sql = dw_1.getsqlselect() 

 

f_split_sql(ls_sql, ls_select, ls_from, ls_where, ls_group, ls_order)