In SQLite, the ->> operator extracts a subcomponent from a JSON document and returns an SQL representation of that subcomponent.
The ->> operator was first introduced in SQLite version 3.38.0 (released on 22 February 2022).
Tag: operators
SQLite -> Operator
In SQLite, the -> operator extracts a subcomponent from a JSON document and returns a JSON representation of that subcomponent.
The -> operator was first introduced in SQLite version 3.38.0 (released on 22 February 2022).
Fix “ERROR 1222 (21000): The used SELECT statements have a different number of columns” when using UNION in MariaDB
When using the UNION operator in MariaDB, you may encounter the following error: “ERROR 1222 (21000): The used SELECT statements have a different number of columns”.
This error occurs when the number of columns returned by each SELECT statement is different.
The way to fix this is to ensure that both SELECT statements return the same number of columns.
SQLite Introduces the -> and ->> Operators for Extracting JSON Subcomponents
Starting with SQLite version 3.38.0 (released on 22 February 2022), we can now use the -> and ->> operators to extract subcomponents of JSON documents.
The aim with these operators is to be compatible with the equivalent MySQL and PostgreSQL operators.
Continue readingFix “ERROR 1222 (21000): The used SELECT statements have a different number of columns” when using UNION in MySQL
If you’re getting “ERROR 1222 (21000): The used SELECT statements have a different number of columns” when using the UNION clause in a MySQL query, it’s probably because the number of columns returned by each SELECT statement is different.
Fix “ERROR 1250 (42000): Table ‘…’ from one of the SELECTs cannot be used in global ORDER clause” when using UNION in MySQL
If you’re getting an error that reads “ERROR 1250 (42000): Table ‘…’ from one of the SELECTs cannot be used in global ORDER clause” when using the UNION clause in a MySQL query, it’s probably because you’re qualifying a column name with its table name.
This doesn’t work in MySQL.
To fix this issue, either remove the table name or use a column alias.
Continue readingFix “ERROR 1054 (42S22): Unknown column ‘…’ in ‘order clause'” when using UNION in MySQL
If you’re getting error “1054 (42S22): Unknown column ‘…’ in ‘order clause'” when using the UNION clause in MySQL, it could be because you’re trying to reference an aliased column by its column name.
Fix “ERROR 1250 (42000): Table ‘…’ from one of the SELECTs cannot be used in ORDER clause” in MariaDB
If you’re getting “ERROR 1250 (42000): Table ‘…’ from one of the SELECTs cannot be used in ORDER clause”, it’s probably because you’re qualifying a column name with its table name when using an operator such as UNION, INTERSECT, or EXCEPT in MariaDB.
To fix this, either remove the table name or use a column alias.
Continue readingSQLite INTERSECT Operator
In SQLite, the INTERSECT operator is used to create a compound SELECT statement that returns the intersection of the results of the left and right SELECT statements. In other words, it combines two queries, but returns only those rows that are returned in both queries.
SQLite EXCEPT Operator
In SQLite, the EXCEPT operator can be used to create a compound SELECT statement that returns the subset of rows returned by the left SELECT that are not returned by the right SELECT.