diff --git a/README.md b/README.md index 3a549f3..83daf2c 100644 --- a/README.md +++ b/README.md @@ -189,25 +189,25 @@ These components are − Following are some of the most commonly used constraints available in SQL − -### NOT NULL Constraint +### !) NOT NULL Constraint − Ensures that a column cannot have a NULL value. -### DEFAULT Constraint +### 2) DEFAULT Constraint − Provides a default value for a column when none is specified. -### UNIQUE Constraint +### 3) UNIQUE Constraint − Ensures that all the values in a column are different. -### PRIMARY Key +### 4) PRIMARY Key − Uniquely identifies each row/record in a database table. -### FOREIGN Key +### 5) FOREIGN Key − Uniquely identifies a row/record in any another database table. -### CHECK Constraint +### 6) CHECK Constraint − The CHECK constraint ensures that all values in a column satisfy certain conditions. -### INDEX +### 7) INDEX − Used to create and retrieve data from the database very quickly. # Data Integrity 🚧