In this article we will discuss the working of SQL Dates. The most important part is that the format of data inserted should always match the data column in the table/database: Note: if column contains ‘ Date ‘ field , then it will work normal. However a combination of (Date+ time) field causes complexity . …
SQL UNIQUE Constraint are used while creating the table. The SQL UNIQUE Constraint make sure that all values in a column are ‘UNIQUE’ . It could be derived that ‘PRIMARY KEY’ and ‘ UNIQUE ‘constraint provides uniqueness to the table. Important: ‘Primary key’ and ‘ UNIQUE’ provides uniqueness to the table There could be only …
SQL NOT NULL Constraint SQL NOT NULL Constraint are used while creating the table. By default , attributes(Column) in a table can hold NULL values. ‘NOT NULL’ enforces a column to not accpet ‘NULL’ Values. Some columns in table are important and if a database administrator never wants to see a ‘NULL’ value in the …
SQL PRIMARY KEY Constraint: SQL PRIMARY KEY is a Field in a table which uniquely identifies each record in a database table. Primary key ought to have ‘UNIQUE’ values. Primary key will never have ‘NULL’ values. Note: A table can only have one primary keys, which may contain one or multiple fields. Type of Keys: …
Overview of SQL: A database is a systematic collection of data. Database systems are used to store, access, delete data. furthermore, it also systematically organize data in a database.This article briefly discuss about the SQL DROP DB(database) . Consider a cafeteria, which provides snacks and other eatable item to its customers. Traditionally, the snacks, juice, and other …