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11 Cards in this Set
- Front
- Back
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How would you find out the total number of rows in a table?
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Use SELECT COUNT(*) ... in query
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How do you eliminate duplicate values in SELECT ?
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Use SELECT DISTINCT ... in SQL query
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How you insert records into a table ?
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Using SQL INSERT statement
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How do you delete record from a table ?
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Using DELETE statement
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What's the difference between a primary key and a unique key?
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Primary key wont allow nulls, unique key allow nulls.
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What is a join and explain different types of joins?
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INNER JOIN
OUTER JOIN LEFT OUTER JOIN RIGHT OUTER JOIN FULL OUTER JOIN INNER JOIN |
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What is a transaction ?
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transaction is a logicl unint of work. All steps must be commited or rolled back.
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What is ACID ?
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Atomicity, Consistency, Isolation and Durability, these are properties of a transaction.
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What is Normalisation ?
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In relational database design, the process of organizing data to minimize redundancy. Results in a series of distinct yet related tables.
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What is Stored Procedure?
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A stored procedure is a named group of SQL statements that have been previously created and stored in the server database
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What is Trigger?
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A trigger is a SQL procedure that initiates an action when an event (INSERT, DELETE or UPDATE) occurs. Triggers are stored in and managed by the DBMS.
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