1. Which statement issues a lock on tables?
Answer & Solution
Answer: Option C
Solution:
This question is about how you control access to data in a MySQL database. Think of it like a library - you need to check out a book before you can read it. In MySQL, you need to "lock" a table before you can make changes to it. Here's the breakdown: * Option A: ISSUE LOCK - This isn't a valid command in MySQL. * Option B: LOCK ISSUE - Again, not a valid command in MySQL. * Option C: LOCK TABLES - This is the correct answer! It's the command used to explicitly lock tables, preventing others from modifying them while you're working. * Option D: ISSUE LOCKS - This isn't a valid command in MySQL.
So, the answer is Option C: LOCK TABLES
2. Which mode is used to turn on strict mode and all of the additional restrictions?
Answer & Solution
Answer: Option C
Solution:
This question is about MySQL strict mode, which is a way to make your SQL queries more accurate and prevent potential errors. Imagine strict mode like a set of rules that make your database behave more predictably. It helps you avoid things like accidentally using data in the wrong way or creating tables that aren't well-structured.
Let's look at the options:
* Option A: STRICT_ALL_TABLES - This is a setting for individual tables, not a global mode for the entire database.
* Option B: ERROR_FOR_DIVISION_BY_ZERO - This option focuses only on division by zero errors, not all strict mode features.
* Option C: TRADITIONAL - This is the correct answer! TRADITIONAL mode enables strict mode and a bunch of additional checks to ensure your SQL queries are accurate and reliable.
* Option D: ERROR_WHEN_DIVIDE_BY_ZERO - Similar to Option B, this focuses on a specific error scenario, not the full set of strict mode rules.
So, TRADITIONAL mode is the mode you want to use if you want to turn on strict mode and all its helpful restrictions.
3. The number of rows in the table is 10. Suppose all rows are deleted. The new row starts with sequence number . . . . . . . .
Answer & Solution
Answer: Option B
Solution:
This question is about how MySQL handles sequence numbers when you delete all the rows in a table. Here's the breakdown:
Imagine a table like a list where each row has a unique number. This number is used to identify each row, kind of like a name tag.
When you delete all the rows, you're essentially erasing the entire list. Now, if you add a new row, MySQL will give it the next available sequence number. Since all the old rows are gone, the new row will get the number that would have been used for the next row if you hadn't deleted everything.
In our case, the table had 10 rows, so the next available number is 11.
Therefore, the correct answer is Option A: 11
4. The DECIMAL used for expressions containing only exact values with fractional part is of digit precision . . . . . . . .
Answer & Solution
Answer: Option C
Solution:
This question is about DECIMAL data type in MySQL. DECIMAL is used to store exact numeric values, which means numbers with a fixed number of decimal places.
The question asks about the digit precision of DECIMAL when used with expressions containing only exact values with fractional parts.
This means we are working with numbers like 1.2345, 0.0001, etc.
In such cases, MySQL uses a default precision for DECIMAL.
Let's look at the options:
* Option A: 32 * Option B: 64 * Option C: 65 * Option D: 16
The correct answer is Option B: 64.
This means that DECIMAL can hold up to 64 digits of precision for exact values with fractional parts in MySQL.
Remember: This is the default precision. You can specify a different precision using the DECIMAL(M, D) syntax, where M is the total number of digits and D is the number of digits after the decimal point.
5. INFORMATION_SCHEMA is more portable than SHOW statements.
Answer & Solution
Answer: Option A
Solution:
This question asks if using INFORMATION_SCHEMA is more portable than using SHOW statements in MySQL.
Let's break it down:
* INFORMATION_SCHEMA: This is a special database in MySQL that provides information about the structure of other databases and tables. It's like a directory that tells you what's inside the database system.
* SHOW Statements: These are MySQL commands used to display information about different aspects of the database, like tables, databases, users, etc.
Portability: This means how easily something can be transferred or used in different environments (like different versions of MySQL or other databases).
Why INFORMATION_SCHEMA is more portable:
* Standardized Structure: INFORMATION_SCHEMA is a standard feature in MySQL and other databases, so the information it provides is structured in a consistent way.
* Consistent Syntax: The queries you use to access information from INFORMATION_SCHEMA are similar across different versions of MySQL.
Why SHOW statements can be less portable:
* Version Differences: The syntax of SHOW statements and the information they provide might change slightly between different versions of MySQL.
* Database-Specific: Some SHOW statements might be unique to MySQL and not available in other databases.
Therefore, the answer is A: True**
INFORMATION_SCHEMA is generally more portable than SHOW statements because it follows a standardized approach across different environments.
6. What are the results of the following SQL commands if col is an integer column?
1. SELECT * FROM mytbl WHERE num_col = '4';
2. SELECT * FROM mytbl WHERE num_col = 4;
1. SELECT * FROM mytbl WHERE num_col = '4';
2. SELECT * FROM mytbl WHERE num_col = 4;
Answer & Solution
Answer: Option A
Solution:
This question tests your understanding of how MySQL handles data types in comparisons. Let's break it down:
Understanding the Code:
Both SQL statements are trying to select data from a table named 'mytbl' where the column 'num_col' matches a specific value.
Key Difference:
The difference lies in how the value is written:
* Statement 1: `SELECT * FROM mytbl WHERE num_col = '4';` uses single quotes around the number '4'. This means MySQL treats '4' as a string, not an integer.
* Statement 2: `SELECT * FROM mytbl WHERE num_col = 4;` uses no quotes. This means MySQL treats 4 as an integer.
How MySQL Handles Data Types
MySQL is quite flexible in how it handles data types during comparisons. When you compare a string to an integer, MySQL will attempt to implicitly convert the string to an integer. This is done by removing any leading or trailing spaces and then trying to interpret the string as a number.
The Answer:
If 'num_col' is an integer column, both statements will likely produce the same results. MySQL will implicitly convert '4' (string) to 4 (integer) in the first statement, allowing the comparison to work correctly.
Therefore, the answer is Option A: same.
Important Note: While this will often work, it's best practice to always use the correct data type when comparing values. Using the appropriate data type ensures consistency and avoids potential errors in cases where implicit conversions might not be successful.
7. What can be used as an alternative to mysqlconfig?
Answer & Solution
Answer: Option A
Solution:
This question asks about an alternative to mysqlconfig. mysqlconfig is a tool used to configure MySQL.
Out of the given options, pkg-config is the correct alternative to mysqlconfig.
pkg-config is a tool used to find the configuration files for libraries. It helps you determine where libraries are installed on your system and what flags need to be used when compiling your program.
The other options, dkg-config, rkg-config, and qkg-config, are not actual tools or commands.
So the answer is Option A: pkg-config.
8. The event scheduler does not run by default.
Answer & Solution
Answer: Option A
Solution:
This question is about the MySQL Event Scheduler, a feature that allows you to schedule tasks to run automatically at specific times or intervals.
The question asks whether the Event Scheduler runs by default.
The answer is True.
The Event Scheduler is disabled by default in MySQL. This means that you need to enable it manually before you can use it.
To enable the Event Scheduler, you can use the following command:
SET GLOBAL event_scheduler = ON;
Once you have enabled the Event Scheduler, you can create events using the CREATE EVENT statement.
So the correct answer is Option A: True
9. What is xyz in the following SQL statement?
DELETE FROM xyz WHERE abc = 5;
DELETE FROM xyz WHERE abc = 5;
Answer & Solution
Answer: Option B
Solution:
This SQL statement is used to delete data from a table. Let's break it down:
DELETE FROM - This part tells the database we want to remove data.
xyz - This is the name of the table where we want to delete data.
WHERE abc = 5 - This is a condition that specifies which data to delete. It means we'll delete only the rows where the column named 'abc' has the value 5.
So, the answer is Option B: table name
xyz represents the name of the table from which data will be deleted.
10. Which flag is used to compile client programs that use MySQL header files?
Answer & Solution
Answer: Option B
Solution:
This question is about compiling programs that talk to a MySQL database. Let's break it down: * MySQL header files are like instructions that tell your program how to talk to MySQL.
* Compiling turns your code into something the computer can understand.
* Flags are special commands you give the compiler to do specific things.
The flag you're looking for helps the compiler find these MySQL header files. Here's how the options work:
* -O is used for optimization, not finding header files.
* -I is the correct answer! It tells the compiler to look for header files in a specific directory.
* -U is for user settings, not header files.
* -A isn't a standard compiler flag.
So the answer is Option B: -I.
Read More Section(MySQL Miscellaneous)
Each Section contains maximum 100 MCQs question on MySQL Miscellaneous. To get more questions visit other sections.
- MySQL Miscellaneous - Section 1
- MySQL Miscellaneous - Section 2
- MySQL Miscellaneous - Section 3
- MySQL Miscellaneous - Section 4
- MySQL Miscellaneous - Section 5
- MySQL Miscellaneous - Section 6
- MySQL Miscellaneous - Section 7
- MySQL Miscellaneous - Section 8
- MySQL Miscellaneous - Section 9
- MySQL Miscellaneous - Section 11
- MySQL Miscellaneous - Section 12