How do I decode a value in SQL query?
The basic syntax for writing DECODE function in SQL is as follows: DECODE (expression , search_1, result_1[, search_2, result_2], …,[,search_n,result_n] [, default]); The parameters used in the above mentioned syntax are: expression: expression argument is the value which is to be searched and compared with.
How do you decode in SQL w3schools?
SELECT name, DECODE ( student_id, 1, ‘Tom’, 2, ‘Mike’, 3, ‘Harry’, ‘Jim’) result FROM students; Explanation: Here, each student_id value will be compared one by one by the DEFAULT function. The default value ( ‘Jim’ ) will be returned if no matches are found.
How does decode work in Oracle?
DECODE compares expr to each search value one by one. If expr is equal to a search , then Oracle Database returns the corresponding result . If no match is found, then Oracle returns default . If default is omitted, then Oracle returns null.
What is equivalent of Decode in SQL Server?
In SQL Server the equivalent code is CASE statement. Here are the examples regarding how DECODE can be written in SQL Server.
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 does SQL decode work?
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.
Can we use decode inside decode?
It is possible to use DECODE, but you’d have to use nested DECODEs and you’d end up with something that’s much harder to read, understand and therefore maintain.
What is difference between SQL and MySQL?
In a nutshell, SQL is a language for querying databases and MySQL is an open source database product. SQL is used for accessing, updating and maintaining data in a database and MySQL is an RDBMS that allows users to keep the data that exists in a database organized. SQL does not change (much), as it is a language.
Which is better decode or case in Oracle?
CASE is better than DECODE because it is easier to read, and can handle more complicated logic. As far as performance goes, there is minimal difference between CASE and DECODE, so it should not be a factor in your decisions.
Can we use null in Decode Oracle?
DECODE. The DECODE function is not specifically for handling null values, but it can be used in a similar way to the NVL function, as shown by the following example.
How do I use NVL2?
NVL2 lets you determine the value returned by a query based on whether a specified expression is null or not null. If expr1 is not null, then NVL2 returns expr2 . If expr1 is null, then NVL2 returns expr3 . The argument expr1 can have any datatype.
What is decode in Snowflake?
Compares the select expression to each search expression in order. As soon as a search expression matches the selection expression, the corresponding result expression is returned. DECODE in Snowflake is different from the DECODE function in PostgreSQL, which converts data into different encodings.
Can we use decode in SQL Server?
In Oracle, you can use DECODE function to evaluate a list of expressions, and if a value is matched return the corresponding result. In SQL Server, you can use CASE expression that is also supported by Oracle. Note that NULL values in DECODE function and CASE expression are handled differently .
What is NVL in SQL?
NVL lets you replace null (returned as a blank) with a string in the results of a query. If expr1 is null, then NVL returns expr2 .