diff options
| -rw-r--r-- | sql.html.markdown | 24 |
1 files changed, 12 insertions, 12 deletions
diff --git a/sql.html.markdown b/sql.html.markdown index 200f4f98..392b0edf 100644 --- a/sql.html.markdown +++ b/sql.html.markdown @@ -27,7 +27,7 @@ DROP DATABASE someDatabase; SHOW DATABASES; -- Use a particular existing database. -USE employees; +USE employees; -- Select all rows and columns from the current database's departments table. -- Default activity is for the interpreter to scroll the results on your screen. @@ -43,12 +43,12 @@ SELECT dept_no, SELECT * FROM departments LIMIT 5; -- Retrieve dept_name column values from the departments --- table where the dept_name value has the substring "en". -SELECT dept_name FROM departments WHERE dept_name LIKE "%en%"; +-- table where the dept_name value has the substring 'en'. +SELECT dept_name FROM departments WHERE dept_name LIKE '%en%'; -- Retrieve all columns from the departments table where the dept_name --- column starts with an "S" and has exactly 4 characters after it. -SELECT * FROM departments WHERE dept_name LIKE "S____"; +-- column starts with an 'S' and has exactly 4 characters after it. +SELECT * FROM departments WHERE dept_name LIKE 'S____'; -- Select title values from the titles table but don't show duplicates. SELECT DISTINCT title FROM titles; @@ -60,8 +60,8 @@ SELECT DISTINCT title FROM titles ORDER BY title; SELECT COUNT(*) FROM departments; -- Show the number of rows in the departments table that --- have "en" as a substring of the dept_name value. -SELECT COUNT(*) FROM departments WHERE dept_name LIKE "%en%"; +-- have 'en' as a substring of the dept_name value. +SELECT COUNT(*) FROM departments WHERE dept_name LIKE '%en%'; -- A JOIN of information from multiple tables: the titles table shows -- who had what job titles, by their employee numbers, from what @@ -89,13 +89,13 @@ CREATE TABLE tablename1 (`fname` VARCHAR(20),`lname` VARCHAR(20)); -- table has been defined to accept these values as appropriate for it. INSERT INTO tablename1 VALUES('Richard','Mutt'); --- In tablename1, change the fname value to "John" --- for all rows that have an lname value of "Mutt". -UPDATE tablename1 SET fname="John" WHERE lname="Mutt"; +-- In tablename1, change the fname value to 'John' +-- for all rows that have an lname value of 'Mutt'. +UPDATE tablename1 SET fname='John' WHERE lname='Mutt'; -- Delete rows from the tablename1 table --- where the lname value begins with "M". -DELETE FROM tablename1 WHERE lname like "M%"; +-- where the lname value begins with 'M'. +DELETE FROM tablename1 WHERE lname like 'M%'; -- Delete all rows from the tablename1 table, leaving the empty table. DELETE FROM tablename1; |