oracleI基础入门(6)--sql语句-Substring SQL 中的 substring 函数是用来抓出一个栏位资料中的其中一部分。这个函数的名称在不同 的数据库中不完全一样: MySQL: SUBSTR(), SUBSTRING() Oracle: SUBSTR() 最常用到的方式如下 (在这里我们用SUBSTR()为例): SUBSTR(str,pos): 由<str>中,选出所有从第<pos>...
示例如下(仅在这里说明left和right, substring就不说了, 一样的): sql server下的 --左取两个字符 select left('abc', 2) --- ab (1 row(s) affected) --右取两个字符 select right('abc', 2) --- bc (1 row(s) affected) oracle中 --左取两个字符 SQL> select substr('abc', 1, 2) ...
This Oracle tutorial explains how to use the Oracle / PLSQL REGEXP_SUBSTR function with syntax and examples. This function, introduced in Oracle 11g, will allow you to extract a substring from a string using regular expression pattern matching.
Let us take another example of a substring in Oracle SQL. I used the query SUBSTR (‘HELLO’, -2, 2), note that the negative number used in the start position, here the negative number -2 at the start position means it will start from the opposite direction of the string ‘HELLO’ ...
將SUBSTR 函式呼叫轉換為 SUBSTRING 函式呼叫SSMA 可以根據參數數目,將 OracleSUBSTR函式呼叫轉換成 SQL Serversubstring函式呼叫。 如果 SSMA 無法轉換SUBSTR函式呼叫,或不支援參數數目,SSMA 會將SUBSTR函式呼叫轉換成自訂 SSMA 函式呼叫。 如果您選取 [是],SSMA 會將使用三個參數的SUBSTR函式呼叫轉換成 SQL Serve...
As the start_position is -1, it starts at the first character before the end of the string. Because the length is greater than 1, it returns the whole substring. Example 4: This example shows the last 5 characters of the string. ...
(char, position [, substring_length ]) Parameters: Behavior when position: If the position is 0, then it is treated as 1. If the position is positive, then Oracle counts from the beginning of char to find the first character. If the position is negative, then Oracle counts backward from...
“项目设置”对话框的“转换”页面包含一些设置,用来自定义 SSMA 如何将 Oracle 语法转换为 SQL Server 语法。 “项目设置”和“默认项目设置”对话框中提供了“转换”窗格: 要指定用于所有 SSMA 项目的设置,请在“工具”菜单上单击“默认项目设置”,从“迁移目标版本”下拉列表中选择需要为其查看或更改设置...
Fixed-length character data type which uses the UNICODE UCS-2 character set. n must be a value in the range 1 to 4000. SQL Server storage size is two times n. Note: Microsoft SQL Server storage size is two times n. The Oracle Migration Workbench maps columns sizes using byte semantics,...
-- The following SQL query uses the INSTR function to find the position of the substring 'Oracle' within the string 'Oracle Database'. -- The search starts from the 20th character in the string. SELECT INSTR('Oracle Database', -- The string in which we are searching for the substring ...