跪求一个菜鸟问题……555555555555555555

[werdcd]

是这样的， 我想写一个sql语句（在interbase里面）——找到一个表的一个字段（比如说叫a），同时找到另一个表的同一字段a。我要的是找到两个表的a字段中同时存在的记录，简单吧，不过俺不会啊……%%%%%%%%%%大哥们，在线等

[werdcd]

怎么没人答啊，啊！！完了完了，大家帮忙啊………………%%%%%%%%%%苦命的偶…………

[werdcd]

我晕哦，都怎么了啊……说话啊 ！！！大哥们，行行好吧……

[耙子]

select a
from table1
where a in (select a from table2)

[renjin]

可以用pazee哥的，也可以用一下
select a
from table1,table2
where ???=???

[noproblem12]

嘿嘿，还是多看看sql语言的书把

耙子和点点的都对

顺便给你sql语句的详细参考

SELECT [TRANSACTION transaction]
[DISTINCT | ALL]
{* | <val> [, <val> 匽}
[INTO :var [, :var 匽]
FROM <tableref> [, <tableref> 匽
[WHERE <search_condition>]
[GROUP BY col [COLLATE collation] [, col [COLLATE collation] 匽
[HAVING <search_condition>]
[UNION <select_expr> [ALL]]
[PLAN <plan_expr>]
[ORDER BY <order_list>]
[FOR UPDATE [OF col [, col 匽]];

<val> = {
col [<array_dim>] | :variable
| <constant> | <expr> | <function>
| udf ([<val> [, <val> 匽])
| NULL | USER | RDB$DB_KEY | ?
} [COLLATE collation] [AS alias]
<array_dim> = [[x:]y [, [x:]y 匽]
<constant> = num | 'string' | charsetname 'string'
<function> = COUNT (* | [ALL] <val> | DISTINCT <val>)
| SUM ([ALL] <val> | DISTINCT <val>)
| AVG ([ALL] <val> | DISTINCT <val>)
| MAX ([ALL] <val> | DISTINCT <val>)
| MIN ([ALL] <val> | DISTINCT <val>)
| CAST (<val> AS <datatype>)
| UPPER (<val>)
| GEN_ID (generator, <val>)

<tableref> = <joined_table> | table | view | procedure
[(<val> [, <val> 匽)] [alias]
<joined_table> = <tableref> <join_type> JOIN <tableref>
ON <search_condition> | (<joined_table>)
<join_type> = [INNER] JOIN
| {LEFT | RIGHT | FULL } [OUTER]} JOIN

<search_condition> = <val> <operator> {<val> | (<select_one
>)}
| <val> [NOT] BETWEEN <val> AND <val>
| <val> [NOT] LIKE <val> [ESCAPE <val>]
| <val> [NOT] IN (<val> [, <val> 匽 | <select_list>)
| <val> IS [NOT] NULL
| <val> {>= | <=}
| <val> [NOT] {= | < | >}
| {ALL | SOME | ANY} (<select_list>)
| EXISTS (<select_expr>)

| SINGULAR (<select_expr>)
| <val> [NOT] CONTAINING <val>
| <val> [NOT] STARTING [WITH] <val>
| (<search_condition>)
| NOT <search_condition>
| <search_condition> OR <search_condition>

| <search_condition> AND <search_condition>
<operator> = {= | < | > | <= | >= | !< | !> | <> | !=}
<plan_expr> =
[JOIN | [SORT] [MERGE]] ({<plan_item> | <plan_expr>}
[, {<plan_item> | <plan_expr>} 匽)

<plan_item> = {table | alias}

{NATURAL | INDEX (<index> [, <index> 匽)| ORDER <index>}
<order_list> =
{col | int} [COLLATE collation]
[ASC[ENDING] | DESC[ENDING]]
[, <order_list> 匽

Argument Description
expr A valid SQL expression that results in a single value
select_one A SELECT on a single column that returns exactly one value
select_list A SELECT on a single column that returns zero or more rows
select_expr A SELECT on a list of values that returns zero or more rows
?

[erickleung]

这样的回答, 高手都吓跑了.

楼主既然这样问, 你相信以他现时的功力, 可以即时冲破'任督'二脉吗?
基本功是必需, 别人都不能帮, 如果他可以有例可模仿并成功了, 自然有兴趣继续.

除了先前的例子, 他也可以尝试.
select field1, field2, ... from Table1
join Table2 on Table1.keyA=Table2.KeyA
where <other conditions>
order by ....

还有许多方式, 留待他自己发掘.