oracle blob 文本搜索
是否可以使用 sql 语句搜索 blob 文本?我可以选择 * from $table where f1 like '%foo%' 如果 f1 是 varchar,那么 f1 是一个 blob 怎么样?这有什么对应的部分吗?
Is it possible to search through blob text using sql statement? I can do select * from $table where f1 like '%foo%' if the f1 is varchar, how about f1 is a blob? Any counter part for this?
推荐答案
这很有可能而且很容易做到.
This is quite possible and easy to do.
只需将 dbms_lob.instr 与 utl_raw.cast_to_raw 结合使用
Simply use dbms_lob.instr in conjunction with utl_raw.cast_to_raw
因此,在您的情况下,如果 t1 是 BLOB,则选择将如下所示:
So in your case, if t1 is a BLOB the select would look like:
select *
from table1
where dbms_lob.instr (t1, -- the blob
utl_raw.cast_to_raw ('foo'), -- the search string cast to raw
1, -- where to start. i.e. offset
1 -- Which occurrance i.e. 1=first
) > 0 -- location of occurrence. Here I don't care. Just find any
;
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