A Little Noise

CREATE TABLE myTable (
 id INT,
 string varchar(100) DEFAULT NULL
);
INSERT INTO myTable (id, string) VALUES (1, "First"), (2, NULL);
UPDATE myTable SET string = CONCAT(id, " has the value ", string);
SELECT * FROM myTable;

What is the output?
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+------+-----------------------+
| id   | string                |
+------+-----------------------+
|    1 | 1 has the value First |
|    2 | NULL                  |
+------+-----------------------+

What would result from the following?

CREATE TABLE my_table (
   id INT
);
INSERT INTO my_table (id) VALUES (2.9), (3), (3.4), (3.9), (4);
SELECT * FROM my_table AS m WHERE my_table.id > 3;

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Assume the following has completed correctly:

CREATE TABLE test (
   charField varchar(5)
);

What is the end difference between the following two statements?

INSERT INTO test (charField) VALUES ("123456");
INSERT INTO test (charField) VALUES ("12345 ");

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What would result from the following?

CREATE TABLE my_table (
id INT
);
INSERT INTO my_table (id) VALUES (2.9), (3), (3.4), (3.9), (4);
SELECT * FROM my_table AS m WHERE my_table.id > 3;
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Assume the following have completed:

GRANT ALL ON test1.* TO 'johnQ'@'localhost' IDENTIFIED BY 'pass1';
GRANT ALL ON test2.* TO 'johnQ'@'localhost' IDENTIFIED BY 'pass2';

User johnQ has a query that joins tables from test1 to tables from test2. How should he log in?

a) Using ‘pass1’.
b) Using ‘pass2’.
c) Using ‘pass1’ and ‘pass2’, separated by a colon.
d) It can’t be done; he must change the two passwords to match.
e) Other (explain)
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SELECT COUNT(DISTINCT someField) FROM someTable;
SELECT DISTINCT someField FROM someTable;

T/F: The value returned by the first will always equal the number of rows returned by the second.
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If I run the following, what will happen?

CREATE TABLE myTable (someField int, UNIQUE (someField));
INSERT INTO myTable VALUES (null);
INSERT INTO myTable VALUES (NULL);

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Assume the following has completed correctly:

CREATE TABLE test (
charField varchar(5)
);


What is the end difference between the following two statements?

INSERT INTO test (charField) VALUES ("123456");
INSERT INTO test (charField) VALUES ("12345 ");
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