The Oracle/PLSQL REGEXP_SUBSTR function is an extension of the SUBSTR function. This function, introduced in Oracle 10g, will allow you to extract a substring from a string using regular expression pattern matc
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. SELECT'Database Star',SUBSTR('Database Star',-5,5)AS...
SUBSTRING expr SUBSTRING(expr,m[,n]) The SUBSTRING function returns a substring of the text string operandexprof lengthncharacters beginning at themth character. If you omit the third operand, the substring starts frommand finishes at the end ofexpr. ...
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 the end of char. If substring_length is omitted, then Oracle returns all characters to the end of char. If substring_length ...
-- The following SQL query uses the INSTR function to locate the position of the first space character (' ') in the string 'THIS IS THE THING'. SELECT INSTR('THIS IS THE THING', -- The string in which we are searching for the space character. ' ' -- The substring to search for...
The Oracle/PLSQL REGEXP_COUNT function counts the number of times that a pattern occurs in a string. This function, introduced in Oracle 11g, will allow you to count the number of times a substring occurs in a string using regular expression pattern matching.Syntax...
Microsoft SQL Server, Sybase Adaptive Server, and Oracle Compared 2-47 Data Manipulation Language Table 2–17 Character Functions in Oracle and Microsoft SQL Server and Sybase Adaptive Server (Cont.) Microsoft SQL Server and Sybase Adaptive Server Oracle Description substring(char_exp, start, length...
Substring matching. Retrieval of text that contains a certain property. User searches for text that contains words that contain a string. Table 2 shows an incomplete list of query operators: Operator ABOUT ACCUMULATE (,) AND (&) Broader Tem (BT, BTG, GTP, BTI) EQUIValence (=) FUZZY ...
3.32 INSTR The INSTR functions search string for substring. The function returns an integer indicating the position of the character in string, or a zero (0) if does not find a match. • INSTR calculates strings using characters as defined by the input character set. • INSTRB uses bytes...
Microsoft® SQL Server™ 2000 使用保留关键字定义、操作和访问数据库。 保留关键字是 SQL Server 使用的 Transact-SQL 语言语法的一部分,用于分析和理解 Transact-SQL 语句和批处理。尽管在 Transact-SQL 脚本中,使用 SQL Server 保留关键字作为标识符和对象名在语法上是可行的,但规定只能使用分隔标识符。