Question

我需要有关如何将此select转换为delete语句的帮助。

SELECT stud_term_sum_div.id_num,   
     stud_term_sum_div.hrs_enrolled,   
     stud_term_sum_div.transaction_sts,   
     student_crs_hist.crs_cde,   
     student_crs_hist.transaction_sts  
  FROM stud_term_sum_div,   
     student_crs_hist  
 WHERE ( stud_term_sum_div.yr_cde = student_crs_hist.yr_cde ) and  
     ( stud_term_sum_div.trm_cde = student_crs_hist.trm_cde ) and  
     ( stud_term_sum_div.id_num = student_crs_hist.id_num ) and  
     ( ( stud_term_sum_div.yr_cde = '2013' ) AND  
     ( stud_term_sum_div.trm_cde = 'FA' ) AND  
     ( stud_term_sum_div.hrs_enrolled >= 3.00 ) AND  
     ( student_crs_hist.transaction_sts = 'D' ) )

Answer 1

最直接的转换如下：

DELETE * FROM stud_term_sum_div
WHERE ( stud_term_sum_div.yr_cde = student_crs_hist.yr_cde ) and  
 ( stud_term_sum_div.trm_cde = student_crs_hist.trm_cde ) and  
 ( stud_term_sum_div.id_num = student_crs_hist.id_num ) and  
 ( ( stud_term_sum_div.yr_cde = '2013' ) AND  
 ( stud_term_sum_div.trm_cde = 'FA' ) AND  
 ( stud_term_sum_div.hrs_enrolled >= 3.00 ) AND  
 ( student_crs_hist.transaction_sts = 'D' ) )

但是，在执行之前，请检查WHERE子句是否确实包含要用于删除的条件。请注意，当WHERE子句中的属性满足所述条件时，此SQL语句将删除整行（a / k / a记录）。

如果您只想从属性中删除数据（而不是整个记录），则需要使用SQL UPDATE语句。（简化）语法如下：

UPDATE <table_name>
SET <attribute1> = <value1>
[, SET <attribute_n> = <value_n>...]
WHERE <conditions on which the record should be updated>

在Bing上搜索，google，＆lt;在此处插入您最喜爱的搜索引擎＆gt;对于“SQL DELETE”或“SQL UPDATE”应该可以获得所需的所有信息（例如MSDN）。

需要有关如何将此select转换为DELETE语句的帮助：

1 个答案: