函数:regexp_matches(string text, pattern text [, flags text]) 说明:Return all captured substrings resulting from matching a POSIX regular expression against the string. See Section 9.7.3 for more information. 对字符
imeans case-insensitive matching or ignoring case. g stands for global; if the g flag is used, this function will replace all occurrences of substrings that match the pattern. The flags parameter is optional.
函数:regexp_matches(string text, pattern text [, flags text])说明:Return all captured substrings resulting from matching a POSIX regular expression against the string. See Section 9.7.3 for more information. 对字符串按正则表达式进行匹配,如果存在则会在结果数组中表示出来 例子:regexp_matches('foob...
在SQL中声明此函数的一种方法是: CREATETYPE__retcompositeAS(f1integer,f2integer,f3integer);CREATEORREPLACEFUNCTIONretcomposite(integer,integer)RETURNSSETOF __retcompositeAS'filename','retcomposite'LANGUAGE C IMMUTABLE STRICT; 另一种方法是使用OUT参数: CREATEORREPLACEFUNCTIONretcomposite(INinteger,INinteger...
Yes, the REPLACE() function can be combined with other string functions like LOWER(), UPPER(), or TRIM() to enhance text processing capabilities. This combination allows for more advanced manipulation, such as cleaning up text by trimming spaces, changing case, and replacing substrings all in...
[octets] strings up to n characters in length strings up to n characters in length - circle - 24bytes <(x,y),r> (center and radius) date decimal [ (p, s)] double precision inet integer interval [ (p) ] json - 4bytes numeric [ (p, s) ] variable float8 float 8bytes - 12 ...
* Since we only care about equality or not-equality, we can avoid all * the expense of strcoll() here, and just do bitwise comparison. In * fact, we don't even have to do a bitwise comparison if we can show * the lengths of the strings are unequal; which might save us from ...
说明：Replace substring替换字符串中任意长度的⼦字串为新字符串 例⼦：overlay('Txxxxas' placing 'hom'from2for4) =4 函数：position(substring in string)说明：Location of specified substring⼦串在⼀字符串中的位置 例⼦：position('om'in'Thomas') =3 函数：substring(string [from int][for ...
如果你关掉了standard_conforming_strings,你在文串常量中写的任何反斜线都需要被双写。 请注意反斜线在串文本里已经有特殊含义了,所以如果你写一个 包含反斜线的模式常量,那你就要在 SQL 语句里写两个反斜线。 因此,写一个匹配单个反斜线的模式实际上要在语句里写四个反斜线。 你可以通过用 ESCAPE 选择一个不...
[^b]atmatches all strings matched by.atexcept "bat". ^[hc]atmatches "hat" and "cat", but only at the beginning of the string or line. [hc]at$matches "hat" and "cat", but only at the end of the string or line. \[.\]matches any single character surrounded by "[" and "]"...