sql.csv

Installation;https://www.youtube.com/watch?v=GIRcpjg-3Eg;sql
Outputs all columns from the table customer (automatically sorted by id);select * from customer;sql
Outputs only the column firstname (no sorting);select firstname from customer;sql
Outputs 2 columns firstname and lastname;select firstname, lastname from customer;sql
With distinct the output occurs only one time if the firstname is the same;select distinct firstname from customer;sql
Everything will be outputed cause the id is unique;select distinct id,firstname from customer;sql
Only when firstname and lastname are equal there will be no outputs;select distinct firstname,lastname;sql
Outputs the row with the id = 0;"select * from customer
    where id = 0";sql
Outputs all rows where the firstname is Janet;"select * from customer
    where firstname = 'Janet'";sql
Outputs all streets which are in the city of Oslo;"select street from customer
    where city = 'Oslo'";sql
all IDs >= 40;...where id >= 40;sql
all IDs except 40 (in some DBs you have to use instead !=);...where id <> 40;sql
everything between 40 and 50;...where id between 40 and 50;sql
some values are checked for id;...where id in (43,44,45);sql
Outputs all rows where id >= 40 and firstname is Robert;"select * from customer
where id >= 40
and firstname = ""Robert""";sql
One of the both conditions have to be fullfilled;"...where id >= 40 or firstname = ""Robert""";sql
combinaton of logical or and and (better to use parantheses);"...where id >= 40 or firstname = ""Robert"" and lastname = ""Fuller""";sql
Outputs rows >=40 sorted ascending for firstname and lastname;"select * from customer
where id >= 40
order by firstname, lastname asc";sql
Output in descending order;...order by firstname, lastname desc;sql
Inserts row in the table with specific values for the columns;"insert into customer
values (50, 'James', 'Karsen', '107 Upland Pl.', 'Dallas')";sql
Inserts row  with streetname = NULL (this is not working for key-columns like id);"insert into customer (id, firstname, lastname, city)
values (51, 'James', 'Karsen', 'Dallas')";sql
Update the row with the id = 51 regarding street;"update customer
set street = '547 Seventh Av.'
where id = 51";sql
Update the strett where firstname James and lastname Karsen;...where firstname = 'James' and lastname = 'Karsen';sql
Delete row with the id = 51;"delete from customer
where id = 51";sql
Outputs the first 5 results (depending on the sorting);select top 5 * from customer;sql
in some DBs also in the following form - oututs the first 10 results;"select * from customer
limit 10";sql
and also in this form in some DBs;"select * from customer
where rownum <= 10";sql
Outputs 10 top percent of the results;select top 10 percent * from customer;sql
"""_"" will be replaced with one char - so the output will be done for eg. Oslo or Oxlo";"select * from computer
where city like 'O_lo'";sql
"Outputs all entries which end with ""lo"" for the column city";... where city like '%lo';sql
"Outputs all entries which start with 2 chars and then the char ""l""";... where city like '__l%';sql
"When there sould be a serach for the percent sign ""%"" - this has to be masked with \%";... where city like '__l\%';sql
Outputs all rows where lastname is NULL;"select * from computer
where lastname is NULL";sql
Outputs all rows where there is some entry in the column lastname;where lastname is NOT NULL;sql
IDs will be selected from the rechnungen-table and will be used for the aboth where-clausel for select *;"select * from customer
where id IN
        (select id from rechnungen
        where date <=3)";sql
Create a new table with name Rechnung;"create table Rechnung
    (
    RechnungsID int,
    CustomerID, int,
    Betrag int
    )";sql
Insert a row in the new table Rechnung with specific values;insert into Rechnung values (1,0,50);sql
Integer;value INT;sql
variable Character;name VARCHAR(255);sql
Bits;bin BINARY (255);sql
Bool (TRUE / FALSE);bool BOOLEAN;sql
variable Bits;VARBINARY(255);sql
SmallInt;SMALLINT;sql
BigInt;BIGINT;sql
Decimal Number (total,decimal places) - 3 beforce decimal places, 2 decimal places;DECIMAL (5,2);sql
Numeric Number;NUMERIC (5,2);sql
Floating Number;FLOAT (10);sql
Double Precision;DOUBLE PRECISION;sql
Date value;DATE;sql
Time value;TIME;sql
Timestamp value;TIMESTAMP;sql
Drop whole table;drop table Rechnung IF EXISTS;sql
Define the Foreign Key with FOREIN KEY (Primary Key in anderer Tabelle) - is referencing to the id in the customer table;"create table Rechnung
    (
    RechnungsID int NOT NULL UNIQUE
    CustomerID int NOT NULL
    Betrag int NOT NULL
    PRIMARY KEY(RechnungsID)
    FOREIGN KEY(CustomerID) REFERENCES Customer(ID)
    )";sql
Using DEFAULT - when something is inserted without specific value - 50 will be used as default value;"create table Rechnung
    (
    RechnungsID int NOT NULL AUTO_INCREMENT
    CustomerID int NOT NULL,
    Betrag int DEFAULT 50,
    PRIMARY KEY(RechnungsID),
    FOREIGN KEY(CustomerID) REFERENCES Customer(ID)
    )";sql
change table Rechnung;alter table Rechnung;sql
add datum-column with datatype date;add Datum Date;sql
drop column betrag from the table;drop column betrag;sql
change column to VARCHAR(255);alter column VARCHAR(255);sql
Outputs firstname + lastname from all customers which exists in the rechnung table;"select firstname, lastname from customer
where id in (select customerID from rechnung)";sql
Outputs all attributes from the customers, which have a rechnung (same as aboth - but for all attributes);"select *
from customer
inner join Rechnung
on customer.ID = rechnung.customerID";sql
Outputs all elements from the left table (customer) - where in the table Rechnung something is inside it will be outputed;...left join Rechnung;sql
Outputs alle elements from the right table (Rechnung) - with informations from both tables;...right join Rechnung;sql
Outputs everything from both sides;...full join Rechnung;sql
Outputs the average;select avg(betrag) from rechnung;sql
Returns the count of the rows;select count(rechnungID) from rechnung;sql
Outputs the count of the rechnungIDs where the betrag is >= the average in the rechnungs table;"select count(rechnungID) from rechnung
where betrag >= (select AVB(betrag) from rechnung)";sql
Outputs maximum betrag from the table;select max(betrag) from rechnung;sql
Outputs the minimum betrag from the table;select min(betrag) from rechnung;sql
Outputs the sum betrag from the table;select sum(betrag) from rechnung;sql
Outputs the firstname as uppercase - sometimes also upper(firstname);select ucase(firstname) from customer;sql
Outputs the firstname as lowercase - sometimes also lower(firstname);select lcase(firstname) from customer;sql
Outputs the length of the string;select len(firstname) from customer;sql
Outputs the actual date + time;select now() from  customer;sql