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MySQL: Quick breakdown of the types of joins [duplicate]
...oin type
JOIN: Return rows when there is at least one match in both tables
LEFT JOIN: Return all rows from the left table, even if there are no matches in the right table
RIGHT JOIN: Return all rows from the right table, even if there are no matches in the left table
FULL JOIN: Return r...
What are DDL and DML?
... the database.
CREATE – to create database and its objects like (table, index, views, store procedure, function and triggers)
ALTER – alters the structure of the existing database
DROP – delete objects from the database
TRUNCATE – remove all records from a table, including all ...
How to get database structure in MySQL via query
Is it possible to somehow get structure of MySQL database, or just some table with simple query?
10 Answers
...
SELECT INTO a table variable in T-SQL
... a complex SELECT query, from which I would like to insert all rows into a table variable, but T-SQL doesn't allow it.
8 An...
PDO Prepared Inserts multiple rows in single query
... fields to create the ? placeholders to bind your parameters.
insert into table (fielda, fieldb, ... ) values (?,?...), (?,?...)....
That is basically how we want the insert statement to look like.
Now, the code:
function placeholders($text, $count=0, $separator=","){
$result = array();
...
Split delimited strings in a column and insert as new rows [duplicate]
...
Here is another way of doing it..
df <- read.table(textConnection("1|a,b,c\n2|a,c\n3|b,d\n4|e,f"), header = F, sep = "|", stringsAsFactors = F)
df
## V1 V2
## 1 1 a,b,c
## 2 2 a,c
## 3 3 b,d
## 4 4 e,f
s <- strsplit(df$V2, split = ",")
data.frame(V1 ...
Bootstrap 3.0 - Fluid Grid that includes Fixed Column Sizes
...
or use display property with table-cell;
css
.table-layout {
display:table;
width:100%;
}
.table-layout .table-cell {
display:table-cell;
border:solid 1px #ccc;
}
.fixed-width-200 {
width:200px;
}
html
<div class="table-layou...
Mocking python function based on input arguments
...om a database and we would like to test this module by mocking pd.read_sql_table method (which takes table_name as argument).
What you can do is to create (inside your test) a db_mock method that returns different objects depending on the argument provided:
def db_mock(**kwargs):
if kwargs['ta...
Possible reasons for timeout when trying to access EC2 instance
.../24
Create Internet Gateway
Attach Internet Gateway to VPC
Create Routing Table
Add Route to Routing Table
Destination: 0.0.0.0/0
Target: <Internet Gateway from earlier>
Create Subnet
CIDR: 10.0.0.0/24
Routing Table: <Routing Table from earlier
It took me a LOT of fumbling to get all...
Migration: Cannot add foreign key constraint
I'm trying to create foreign keys in Laravel however when I migrate my table using artisan i am thrown the following error:
...