string LIKE pattern [ESCAPE escape-character] string NOT LIKE pattern [ESCAPE escape-character] 如果该string匹配了提供的pattern,那么LIKE表达式返回真(和预期的一样,如果LIKE返回真,那么NOT LIKE表达式返回假, 反之亦然。一个等效的表达式是NOT (string LIKE pattern))。 如果pattern不包含百分号或者下划线,那么...
像SqlServer就有锁升级,在持有大量行锁时可能升级为页锁甚至表锁,避免所占用大量内存。 These locks are acquired when internal fields of a row are being updated (or deleted or marked for update). Postgres doesn't remember any information about modified rows in memory and so has no limit to the ...
LIKE ANY(ARRAY[])如果需要相似任意一个参数, 需要使用这个语法 NOT LIKE ALL(ARRAY[])如果想达到不相似任意一个参数, 需要用这个语法 ILIKE ILIKE是不区分大小写的LIKE ILIKE NOT ILIKE ILIKE ANY(ARRAY[]) NOT ILIKE ALL(ARRAY[])
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anyelement、anyarray、anynonarray、anyenum以及anyrange,它们被统称为多态类型。任何使用这些类型声明的函数被称作是一个多态函数。通过使用根据一次特定调用实际传递的数据类型所决定的相关数据类型,一个多态函数能够在多种不同数据类型上操作。 二、用户定义的函数 ...
但是正则表达式运算符~或其求反运算符!~对于该用例来说更简单。要排除varchar_field包含任何给定字符串的...
If any of the upper 25/17 bits are not zero, the code point is broken into multiple 1-byte (UTF-8) or 2-byte (UTF-16) sequences based on someclever rules, One of the very nice features of Unicode is that any code point where the upper 25 bits are zero is exactly the same as...
(p.oid)||') OWNER TO ' || v_new_owner || ';' as a from pg_proc p join pg_namespace nsp ON p.pronamespace = nsp.oid where nsp.nspname = ANY (v_schema) union all select 'ALTER DATABASE "' || current_database() || '" OWNER TO ' || v_new_owner LOOP EXECUTE r.a;...
I need to insert values like: user's log, 'my user', customer's. insert into test values (1,'user's log'); insert into test values (2,''my users''); insert into test values (3,'customer's'); I am getting an error if I run any of the above statements. If there is any...
Question: Is there equivalent functionality to Oracle's ANY_VALUE(...) KEEP (DENSE_RANK FIRST/LAST ORDER BY ...) in PostgreSQL? Related: YouTube: The KEEP clause will KEEP your SQL queries SIMPLE (Oracle) Stack Overflow: Explanation of KEEP in Oracle FIRST/LAST db-ori...