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26.
What does TIMESTAMP ON UPDATE CURRENT_TIMESTAMP data type do?
- On initialization places a zero in that column, on future updates puts the current value of the timestamp in.
27.
Explain TIMESTAMP DEFAULT ‘2006:09:02 17:38:44' ON UPDATE CURRENT_TIMESTAMP
- A default value is used on initialization, a current timestamp is inserted on update of the row.
28.
If I created a column with data type VARCHAR(3), what would I expect to see in MySQL table?
- CHAR(3), since MySQL automatically adjusted the data type.
29.
How would you change a table to InnoDB?
ALTER TABLE techpreparation_questions ENGINE innodb;
30.
When you create a table, and then run SHOW CREATE TABLE on it, you occasionally get different results than what you typed in. What does MySQL modify in your newly created tables?
- VARCHARs with length less than 4 become CHARs
- CHARs with length more than 3 become VARCHARs.
- NOT NULL gets added to the columns declared as PRIMARY KEYs
- Default values such as NULL are specified for each column
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