SQL summary
Format of insert statement:
INSERT INTO <table> (<field>) VALUES <value1>, <value2>, … , <valuen>
//Insert a record with the values to the fields listed
Format of delete statement: (use with caution)
DELETE FROM <table> WHERE <condition> AND/OR <condition>
//Delete the record with the field that fits the condition
Updating Data in a Table:
UPDATE <table> SET <field> = <new value> WHERE <field> = <existing value>
//Change the value in the fields of the record that fits the condition to the new value
Format of order statement
SELECT <field(s)> FROM <table> ORDER BY <field1>, … , <fieldn>
//Order the records alphabetically by the first field then the next field
SELECT <field(s)> FROM <table> ORDER BY <field1> DESC, … , <fieldn> DESC
//Order the records alphabetically in descending order by the first field then the next field
Selecting Data in a Table
SELECT <field(s)> FROM <table>
//Limit the amount of fields on the table
SELECT * FROM <table>
//Show all fields of the table
Format to see specific records
SELECT <field(s)> FROM <table> WHERE <condition>
// Show the records that fit the condition
SELECT <field(s)> FROM <table> WHERE <condition> LIKE <%pattern>
//The records where the pattern exists at the end of the value
LIKE <pattern%>
//The records where the pattern exists at the beginning of the value
LIKE <%pattern%>
//The records where the pattern exists anywhere in the value
SELECT <field(s)> FROM <table> WHERE <condition> AND <condition>
//The records where both the conditions are true
SELECT <field(s)> FROM <table> WHERE <condition> OR <condition>
//The records where either of the conditions are true
SELECT <field(s)> FROM <table> WHERE <field> BETWEEN <value1> AND <value2>
//The records where the field has values between the two values specified
SELECT <field(s)> FROM <table> WHERE <condition> LIMIT <value>
//Only the records before the limit value are shown
SELECT <fields> FROM <table> WHERE <condition> GROUP BY <field>
HAVING (<condition1>, <condition2>…)
//Having is for the conditions for the new result set
NB* use only when using GROUP BY
SELECT DISTINCT <fields> FROM <table>
//Removes all duplicates
Format for word manipulation
SELECT LEFT(<field>,<value>) AS <field> FROM <table>
//characters from left until the value
SELECT RIGHT(<field> , <value>) AS <field> FROM <table>
//all characters from right until the value from right
SELECT MID(<field>, <value1>, <value2>) AS <field> FROM <table>
//all characters from value 1 until the amount of value 2 e.g. (3,2) will give you the 3rd and 4th values
SELECT LENGTH(<field>) AS <field> FROM <table>
//give the length of the field
SELECT CONCAT(<value1>,<value2>,<value3>) AS <field> FROM <table>
//gives the values combined together as one value
Format for date manipulation
SELECT MONTH(<field>) AS <field> FROM <table>
//gives the month of the date
SELECT DAY(<field>) AS <field> FROM <table>
//gives the day of the date
SELECT YEAR(<field>) AS <field> FROM <table> //gives the year of the date
SELECT NOW() AS <field> FROM <table>
//gives the current date from the computer clock
Format for number manipulation
SELECT AVG(<field>) AS <field> FROM <table>
//gives the average of the records for that field
SELECT COUNT(*) FROM <table> WHERE <condition>
//Counts the amount of records in the table with the condition
SELECT MAX(<field>) AS <field> FROM <table>
//Show the record with the biggest value in the field
SELECT MIN(<fields>) AS <field> FROM <table>
//Show the record with the smallest value in the field
SELECT SUM(<field>) AS <field> FROM <table>
//Show total sum of the records in the field
SELECT <field>, COUNT(*) AS <field> FROM <table> WHERE <condition> GROUP BY <field>
//Show the amount of records in every field in the group by condition
SELECT ROUND(<field>,<value>) AS <field> FROM <table>
//Rounds the field off to the “valueth” decimal place e.g. (3.456,1) => 3.5
SELECT RAND( ) AS <field> FROM <table>
//Gives a random number from 0 to 0.9999…
SELECT MOD(<value>,<value>) AS <field> FROM <table>
//Gives the remainder of the first value after dividing by the second value, same as the % for java
SELECT TRUNCATE(<field manipulated>) FROM <table>
//Gives the value in the same format as the field
SELECT <field> FROM <table> WHERE <field> IN (<value>, <value> …)
//Same as saying <field> = <value> OR <field> = <value> …
Format for table joins
SELECT <table>.<field> FROM <table1>, <table2> WHERE <table1>.<field> = <table2>.<field>
//Inner join by just using where conditions
SELECT <table>.<field> FROM <table1> INNER JOIN <table2> ON <table1>.<field> = <table2>.<field>
//Inner join with full format and the order of the tables do not matter
SELECT <table>.<field> FROM <table1>
LEFT OUTER JOIN <table2> ON <table1>.<field> = <table2>.<field>
//Outer join, table 1 contains info and the second has null value
SELECT <table>.<field> FROM <table1>
RIGHT OUTER JOIN <table2> ON <table1>.<field> = <table2>.<field>
//Outer join, table 2 contains info and the first has null value
SELECT <table>.<field> FROM <table1>
FULL JOIN <table2> ON <table1>.<field> = <table2>.<field>
//Outer join, either table has info and either can have null value
Order of the select
SELECT DISTINCT <field>
FROM <table>
WHERE <condition>
GROUP BY <field>
HAVING <condition>
ORDER BY <field>
LIMIT <value>
SQL Summary of all functions that the IEB could possibly ask in exams. From: http://webcheatsheet.com/sql
AVG
SELECT Position, Avg(Salary) AS AvgSalary FROM EmployeeStatisticsTable GROUP BY Position
Calculates the arithmetic mean (the sum of the values divided by the number of values).
CHR
SELECT Chr(37) AS Char1, Chr(100) AS Char2 FROM Orders
It returns the character associated with the specified ANSI code.
COUNT
SELECT SellerID, Count(Item) AS Quantity FROM Antiques GROUP BY SellerID
Interval
Description
It calculates the number of records in a select query.
yyyy
Year
DATE
SELECT Date() AS Dates FROM Orders It returns a value such as '05.05.2005',
q
Quater
Similar: NOW, except Now returns date and time
m
Month
DATEADD
SELECT DateAdd('d',45, Now()) AS Diff FROM Orders
y
Day of year
DATEDIFF
Format: DateAdd ( interval, number, date )
w
Weekday
SELECT DateDiff('d',#05/05/1985#, Now()) AS diff FROM Orders
Format: DateDiff ( interval, date1, date2)
ww
Week
The interval is the interval of time you want to add/subtract.
h
Hour
The number is the number of intervals you want to add/subtract.
n
Minute
It can be positive (to get dates in the future) or
s
Second
negative (to get dates in the past).
DAY
FIRST
FIX
INT
FORMAT
IIF
ISNULL
LCASE / UCASE
LEFT
The date is the date to which the interval is added/subtracted.
SELECT Day(bdate) AS bdDay FROM Orders Similar: hour, minute, month, year, etc. To get part of a date.
SELECT First([ItemDesired]) AS One FROM Orders
It returns a field value from the first record in the result set of a query. Same as top 1. Opposite: LAST
SELECT Fix([Price]) AS intPrice FROM Antiques Same as: SELECT int([Price]) AS intPrice FROM Antiques
It returns the integer portion of a number.
SELECT Format([BirthDate],'yyyy/mm/dd') AS bd FROM EmployeeAddressTable;
SELECT Format([Salary],'General Number') AS SalaryNum FROM EmployeeStatisticsTable;
It returns a string containing an expression formatted according to instructions in the expression.
Format
Explanation
General Date
Displays date based on your system settings
Long Date
Displays date based on your system's long date setting
Medium Date
Displays date based on your system's medium date setting
Short Date
Displays date based on your system's short date setting
Long Time
Displays time based on your system's long time setting
Medium Time
Displays time based on your system's medium time setting
Short Time
Displays time based on your system's short time setting
General Number
Displays a number without thousand separators.
Currency
Displays thousand separators as well as two decimal places.
Fixed
Displays at least one digit to the left of the decimal place and two digits to the
right of the decimal place.
Standard
Displays the thousand separators, at least one digit to the left of the decimal place,
and two digits to the right of the decimal place.
Percent
Displays a percent value - that is, a number multiplied by 100 with a percent sign.
Displays two digits to the right of the decimal place.
Scientific
Scientific notation.
Yes/No
Displays No if the number is 0. Displays Yes if the number is not 0.
True/False
Displays True if the number is 0. Displays False if the number is not 0.
On/Off
Displays Off if the number is 0. Displays On is the number is not 0.
SELECT SellerID, BuyerID, Item, IIf([Price]>400,[Price]*1.05,[Price]*1.15) AS Total FROM Antiques
Format: IIf ( expression, truepart, falsepart )
SELECT * FROM tblLearner WHERE isnull(address)
is same as: SELECT * FROM tblLearner WHERE address is null
SELECT LCase([ItemDesired]) AS small FROM Orders To get all in small or capital letters
SELECT Left([ItemDesired],3) AS FirstLetters FROM Orders
It returns the leftmost n characters of a string. Format: Left ( string, length )
LEN
MAX
SELECT Len([ItemDesired]) AS NumChars FROM Orders It returns the length of the specified string.
Select SellerID, Max(Price) as MaxPrice From Antiques Group by SellerID
It returns the maximum of a set of values in a select query.
MID
SELECT Mid([ItemDesired],2,5) AS middle FROM Orders
It returns a string containing a specified number of characters from a string .
Format: Mid( (string, start [, length]) )
MIN
MONTH vs
MONTHNAME
Select SellerID, Min(Price) as MinPrice From Antiques Group by SellerID
It returns the minimum of a set of values in a select query.
Month gives the number and monthName the name, e.g.
SELECT Month(Birthdate) as monthBD from Orders  Answer: 1
SELECT MonthName(Month(Birthdate)) as monthBD from Orders  Answer: January
RIGHT
RND
ROUND
SQR
SUM
WEEKDAY vs
DAY vs
WEEKDAYNAME
Nested SQL
SELECT in
INSERT
SELECT Right([ItemDesired],3) AS LastLetters FROM Orders
It returns the rightmost n characters of a string. Format: Right ( string, length )
It allows you to generate a random number (integer value).
You can specify the random number to be a value between 2 user-specified numbers.
The syntax for the Rnd function in MS Access is: Int ((upperbound - lowerbound + 1) * Rnd + lowerbound)
upperbound  The highest value that the random number can be.
lowerbound  The lowest value that the random number can be.
Example
Int ((6 - 1 + 1) * Rnd + 1)
Result: random number between 1 and 6
Int ((200 - 150 + 1) * Rnd + 150)
Result: random number between 150 and 200
Int ((999 - 100 + 1) * Rnd + 100)
Result: random number between 100 and 999
The problem is that the value of the random number is visited once, and repeated throughout the query
execution. However, if you’d like a random number unique to each record, here’s how to do it:

You need an ID or some other AutoNumber field.

There must be a reference to the value of ID. Because this value changes on every record’s fetch,
the random number re-computes dynamically throughout the execution of the query.
Example: Int ((6 - 1 + 1) * Rnd(ID) + 1)
It will give the SAME random numbers every time you run it, UNLESS you type Randomize in a query and
run it before running this query.
When you run the RANDOMIZE in a query it gives a mistake that you can ignore.
SELECT Round(Avg(Price),2) AS Profit FROM Orders
It returns a number rounded to a specified number of decimal places
SELECT Sqr([BuyerId]) AS SquerRoot FROM Antiques
It returns the square root of a number
Select SellerID, Sum(Price) as TotalSum From Antiques Group by SellerID Having Sum(Price)>57
It returns the sum of a set of values.
SELECT Day(Birthdate) as dayBD from Orders  Answer: 27, e.g. 27 January 2016
SELECT Weekday(day(Birthdate)) as dayBD from Orders  Answer: 4
SELECT Weekdayname(Weekday(day(Birthdate))) as dayBD from Orders  Answer: Wednesday
SELECT * From Orders Where Price > (SELECT AVG(Price) from Orders)
Sometimes you have to add the words ALL or SOME or ANY, e.g.
SELECT UnitPrice FROM PRODUCTS WHERE UnitPrice < ALL
(SELECT TOP 5 UnitPrice FROM Products ORDER BY UnitPrice DESC)
ORDER BY UnitPrice DESC
General Format (with columns specified): INSERT INTO departments (department_id,department_name,
manager_id, location_id) VALUES (70, 'Public Relations', 100, 1700);
Copying Rows from another Table: You can use the INSERT statement to add rows to a table where the
values are derived from existing tables. In place of the VALUES clause, you use a subquery. In this way, you
can easily copy large volumes of data from one table to another with one single SELECT statement. The
number of columns and their data types in the column list of the INSERT clause must match the number of
values and their data types in the subquery. Examples:
Populate the SALES_REPS table with data from the EMPLOYEES table where the job_id is REP.
INSERT INTO sales_reps(id, name, salary, commission_pct)
SELECT employee_id, name, salary, commission_pct FROM employees WHERE job_id LIKE '*REP*';
OR if some are from existing and other’s new, e.g. a new employee that gets a new id (automatically
generated, i.e. not part of the SQL), but the same details as others from the same department
INSERT INTO sales_reps(name, salary, commission_pct)
SELECT “John Smith”, salary, commission_pct FROM employees WHERE job_id LIKE '*REP*';