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Data Types

SQL data types define the type of data that can be stored in a database table's column. Depending on the DBMS, the names of the data types can differ slightly. Here are the general types:

INT​

INT is used for whole numbers. For example:

CREATE TABLE Employees (
    ID INT,
    Name VARCHAR(30)
);

DECIMAL​

DECIMAL is used for decimal and fractional numbers. For example:

CREATE TABLE Items (
    ID INT,
    Price DECIMAL(5,2)
);

CHAR​

CHAR is used for fixed-length strings. For example:

CREATE TABLE Employees (
    ID INT,
    Initial CHAR(1)
);

VARCHAR​

VARCHAR is used for variable-length strings. For example:

CREATE TABLE Employees (
    ID INT,
    Name VARCHAR(30)
);

DATE​

DATE is used for dates in the format (YYYY-MM-DD).

CREATE TABLE Employees (
    ID INT,
    BirthDate DATE
);

DATETIME​

DATETIME is used for date and time values in the format (YYYY-MM-DD HH:MI:SS).

CREATE TABLE Orders (
    ID INT,
    OrderDate DATETIME
);

BINARY​

BINARY is used for binary strings.

BOOLEAN​

BOOLEAN is used for boolean values (TRUE or FALSE).

Remember, the specific syntax for creating tables and defining column data types can vary slightly depending upon the SQL database you are using (MySQL, PostgreSQL, SQL Server, SQLite, Oracle, etc.), but the general concept and organization of data types is cross-platform.