'I am a string in single quotes' "I am a string in double quotes" PHP语法分析器是用成对的引号来判断一个字符串的。因此,所有字符串必须使用同一种单或者双 引号来定义开始和结束。例如,下面的字串定义是不合法的: "I am not a valid string since I have unmatching quote marks' 'Me neither!"...
说明:Return the given string suitably quoted to be used as a string literal in an SQL statement string. Embedded single-quotes and backslashes are properly doubled. 对字符串里两边加上单引号,如果字符串里面出现sql编码的单个单引号,则会被表达成两个单引号 例子:quote_literal('O\'Reilly') = 'O'...
函数 string || string string || non-string or non-string || string bit_length(string) char_length(string) or character_length(string) lower(string) octet_length(string) overlay(string placing string from int [for int]) position(substring in string) substring(string [from int] [for int])...
函数:quote_literal(string text)说明:Return the given string suitably quoted to be used as a string literal in an SQL statement string. Embedded single-quotes and backslashes are properly doubled. 对字符串里两边加上单引号,如果字符串里面出现sql编码的单个单引号,则会被表达成两个单引号 ...
or a superuser chooses to create objects in it. schema的owner默认是该schema下的所有对象的owner,但是PostgreSQL又允许用户在别人的schema下创建对象,所以一个对象可能属于两个owner,而且schema 的owner有 drop对象的权限。 对于两个owner都有drop的权限,这个我个人认为是一个BUG。
octet_length(string) int 字符串中的字节数 select octet_length(‘jack’); 4 convert(string using conversion_name) test 使用指定的转换名字改变编码。转换可以通过CREATE CONVERSION定义,系统中也有一些预定义的转换名字 select convert(‘Postgresql’ using iso_8859_1_to_utf8); UTF8编码的Postgresql convert...
All these functions return the given string suitably quoted to be used as an identifier in an SQL statement string. In the function QUOTE_IDENT, Quotes are added only if necessary. In function QUOTE_LITERAL, embedded single-quotes and backslashes are properly doubled. If a value is passed, ...
In addition to standard_conforming_strings, the configuration parameters escape_string_warning and backslash_quote govern treatment of backslashes in string constants. The character with the code zero cannot be in a string constant. unicode输入格式2 格式2,刚好相反,反斜线不是转义字符时的unicode写法。
In more sophisticated locales, the collation function “normalizes” the input string into a string that can be repeatedly compared by just comparing the bytes. What is an index, anyway? Everyone who works with databases has an intuitive idea of what an index is, but for our purposes, an ...
pg_catalog.pg_get_userbyid(d.datdba)as"Owner",pg_catalog.pg_encoding_to_char(d.encoding)as"Encoding",d.datcollateas"Collate",d.datctypeas"Ctype",pg_catalog.array_to_string(d.datacl,E'\n')AS"Access privileges"FROMpg_catalog.pg_data...