What is the use of Regexp_substr in Oracle?
REGEXP_SUBSTR extends the functionality of the SUBSTR function by letting you search a string for a regular expression pattern. It is also similar to REGEXP_INSTR , but instead of returning the position of the substring, it returns the substring itself.
What does decode in SQL do?
What is DECODE function in SQL? In Oracle, DECODE function allows us to add procedural if-then-else logic to the query. DECODE compares the expression to each search value one by one. If expression is equal to a search, then the corresponding result is returned by the Oracle Database.
What is regular expression in PL SQL?
Regular expressions enable you to search for patterns in string data by using standardized syntax conventions. You specify a regular expression by means of the following types of characters: Metacharacters, which are operators that specify search algorithms. Literals, which are the characters for which you are …
Why To_char is used in SQL?
TO_CHAR function is used to typecast a numeric or date input to character type with a format model (optional).
What is the use of Instr in SQL?
The INSTR functions search string for substring . The function returns an integer indicating the position of the character in string that is the first character of this occurrence.
What is Regexp_extract?
A string function used in search operations for sophisticated pattern matching including repetition and alternation. the string to search for strings matching the regular expression. …
How do I use decode?
The DECODE function returns a value that is the same datatype as the first result in the list. If the first result is NULL, then the return value is converted to VARCHAR2. If the first result has a datatype of CHAR, then the return value is converted to VARCHAR2. If no matches are found, the default value is returned.
How do I use NVL in SQL?
A final example using the NVL function in Oracle/PLSQL is: SELECT NVL(commission, 0) FROM sales; This SQL statement would return 0 if the commission field contained a null value. Otherwise, it would return the commission field.
What is Regexp_like in SQL?
The Oracle REGEXP_LIKE() function is an advanced version of the LIKE operator. The REGEXP_LIKE() function returns rows that match a regular expression pattern. Noted that in SQL standard, REGEXP_LIKE is an operator instead of a function.
Can we use regular expression in SQL query?
The database provides a set of SQL functions that allow you to search and manipulate strings using regular expressions. You can use these functions on any datatype that holds character data such as CHAR, NCHAR, CLOB, NCLOB, NVARCHAR2, and VARCHAR2. A regular expression must be enclosed or wrapped between single quotes.
Can RegEx be used in SQL?
Unlike MySQL and Oracle, SQL Server databases don’t support built-in RegEx functions. However, SQL Server offers the following built-in functions to tackle such complex issues: LIKE. PATINDEX.
What is difference between TO_CHAR and To_date?
1 Answer. to_char function is used to convert the given data into character…. to_date is used to convert the given data into date data formate data type…. eg: to_date(‘070903’, ‘MMDDYY’ ) would return a date value of July 9, 2003.
What is Substr SQL?
SUBSTR: Extracting a Substring From a String Value (SQL)
The SUBSTR function returns a substring of a character value. You specify the start position of the substring within the value. … If the specified length value is longer than the input string, the result is the full input string.
What is convert in SQL?
In SQL Server (Transact-SQL), the CONVERT function converts an expression from one datatype to another datatype. If the conversion fails, the function will return an error. Otherwise, it will return the converted value. TIP: Use the TRY_CONVERT function to return a NULL (instead of an error) if the conversion fails.