SQL Data Types for MySQL, SQL Server, and MS Access - W3Schools
Each column in a database table is required to have a name and a data type. An SQL developer must decide what type of data that will be stored inside each column when creating a table.
MySQL Data Types - W3Schools
An SQL developer must decide what type of data that will be stored inside each column when creating a table. The data type is a guideline for SQL to understand what type of data is expected inside of …
MySQL ALTER TABLE Statement - W3Schools
The data type specifies what type of data the column can hold. For a complete reference of all the data types available in MySQL, go to our complete Data Types reference.
JSON Data Types - W3Schools
Valid Data Types In JSON, values must be one of the following data types: a string a number an object (JSON object) an array a boolean null
PostgreSQL - ALTER TABLE - ALTER COLUMN - W3Schools
To change the data type, or the size of a table column we have to use the ALTER TABLE statement. The ALTER TABLE statement is used to add, delete, or modify columns in an existing table.
SQL NULL Values - IS NULL and IS NOT NULL - W3Schools
A field with a NULL value is a field with no value. If a field in a table is optional, it is possible to insert a new record or update a record without adding a value to this field.
SQL ALTER TABLE Statement - W3Schools
The data type specifies what type of data the column can hold. For a complete reference of all the data types available in MS Access, MySQL, and SQL Server, go to our complete Data Types reference.
ADO Data Types - W3Schools
The table below shows the ADO Data Type mapping between Access, SQL Server, and Oracle: ... * In Oracle 8.0.x - decimal and int are equal to number and number (10).
Python Data Types - W3Schools
Variables can store data of different types, and different types can do different things. Python has the following data types built-in by default, in these categories:
MySQL Date Functions - W3Schools
The most difficult part when working with dates is to be sure that the format of the date you are trying to insert, matches the format of the date column in the database.