We can use the following syntax to drop multiple tables:

    DROP TABLE IF EXISTS B,C,A;

This can be placed in the beginning of the script instead of individually dropping each table.

    SET foreign_key_checks = 0;
    DROP TABLE IF EXISTS a,b,c;
    SET foreign_key_checks = 1;

Then you do not have to worry about dropping them in the correct order, nor whether they actually exist.

N.B. this is for MySQL only (as in the question). Other databases likely have different methods for doing this.

A lazy way of doing this if there are alot of tables to be deleted. 

1. Get table using the below
 - For sql server  - SELECT CONCAT(name,&#39;,&#39;) Table_Name FROM SYS.tables;
 - For oralce - SELECT CONCAT(TABLE_NAME,&#39;,&#39;) FROM SYS.ALL_TABLES;

2. Copy and paste the table names from the result set and paste it after the DROP command.






    declare @sql1 nvarchar(max) 
    SELECT @sql1 =
      STUFF(
             (
               select &#39; drop table dbo.[&#39; + name + &#39;]&#39;
   
               FROM sys.sysobjects AS sobjects
               WHERE (xtype = &#39;U&#39;) AND (name LIKE &#39;GROUP_BASE_NEW_WORK_%&#39;)
               for xml path(&#39;&#39;)
            ),
         1, 1, &#39;&#39;)

      execute sp_executesql @sql1

I just setup the NotePad sample project as described here, but when I try to launch it (Ctrl+F11) I received the following error message box:

&gt; Path for project must have only one
&gt; segment.


![enter image description here][1]

What does this error mean and why is it happening?

(I tried to consult [this article][2], but it seems irrelevant to my problem because I have no getProject anywhere in this copied-verbatim sample project)


  [1]: http://i.stack.imgur.com/iBurr.png
  [2]: http://dushi.co.uk/09/07/2009/error-path-for-project-must-have-only-one-segment/

Android: &quot;Path for project must have only one segment&quot;

I&#39;m new to version control and I understand that &quot;committing&quot; is essentially creating a backup while updating the new &#39;current&#39; version of what you&#39;re working on.

What I don&#39;t understand is what staging for is from a practical perspective. Is staging something that exists in name only or does it serve a purpose? When you commit, its going to commit everything anyway, right?

Edit: I think I may be confusing the terminology. Is a &#39;staged&#39; file the same thing as a &#39;tracked&#39; file?

Why would I want stage before committing in Git?

How to drop multiple tables from one single database at one command.
something like,

    &gt; use test; 
    &gt; drop table a,b,c;

where a,b,c are the tables from database test.




Drop multiple tables in one shot in MySQL

How to drop multiple tables from one single database at one command.
something like,
<pre><code class="hljs language-css">> use test; 
> drop table a,b,c;
</code></pre>
where a,b,c are the tables from database test.

I want to take the whole database. Where do I find the database file?

And is there a way to write the whole database with all data to a text file (like the one in SQL Server)?


How to generate the whole database script in MySQL Workbench?

I&#39;m building a website with MySQL.  I&#39;m using TOAD for MySQL and suddenly I can&#39;t connect to the database as I&#39;m getting an error:

&gt; **&quot;Too many connections&quot;**

Is there any way in Toad for MySQL to view existing connections to be able to kill them or simple close all connections all together?

How to kill MySQL connections

I am working on a moderately complex schema in MySQL Workbench, and the single page of the EER diagram is now full up. Does anyone know how to enlarge it to two or more pages?

How do I enlarge an EER Diagram in MySQL Workbench?

Our standard code section for using JDBC is...

    Connection conn = getConnection(...);
    Statement  stmt = conn.conn.createStatement (ResultSet.TYPE_SCROLL_INSENSITIVE,
                                                    ResultSet.CONCUR_READ_ONLY);
    ResultSet  rset = stmt.executeQuery (sqlQuery);
    
    // do stuff with rset
    
    rset.close(); stmt.close(); conn.close();

**Question 1:** When using Connection Pool, should one close the Connection at the end? If so, isn&#39;t the purpose of pooling lost? And if not, how does the DataSource know when a particular instance of Connection is freed up and can be reused? I am a little confused on this one, any pointers appreciated.

**Question 2:** Is the following method anything close to standard? Looks like an attempt to get a connection from the pool, and if DataSource cannot be established, use the old fashioned DriverManager. We are not even sure which part is getting executed at runtime.
Repeating the question above, should one close the Connection coming out of such a method?

    synchronized public Connection getConnection (boolean pooledConnection)
                                                            throws SQLException {
            if (pooledConnection) {
                    if (ds == null) {
                            try {
                                    Context envCtx = (Context)
                                            new InitialContext().lookup(&quot;java:comp/env&quot;);
                                    ds = (DataSource) envCtx.lookup(&quot;jdbc/NamedInTomcat&quot;);
                                    return ds.getConnection();
                            } catch (NamingException e) {
                                    e.printStackTrace();
                    }}
                    return (ds == null) ? getConnection (false) : ds.getConnection();
            }
            return DriverManager.getConnection(
                    &quot;jdbc:mysql://&quot;+ipaddy+&quot;:&quot;+dbPort +&quot;/&quot; + dbName, uName, pWord);
    }

 Edit: I think we are getting the pooled connection since we do not see a stack trace.
 

Closing JDBC Connections in Pool

Is there any way to get the results from a fetchall() as a dictionary using pymysql?

pymysql fetchall() results as dictionary?

I have a simple list of ~25 words. I have a varchar field in PostgreSQL, let&#39;s say that list is `[&#39;foo&#39;, &#39;bar&#39;, &#39;baz&#39;]`. I want to find any row in my table that has any of those words. This will work, but I&#39;d like something more elegant.

    select *
    from table
    where (lower(value) like &#39;%foo%&#39; or lower(value) like &#39;%bar%&#39; or lower(value) like &#39;%baz%&#39;)

PostgreSQL wildcard LIKE for any of a list of words

Is there a way to set the schema for a query so that in the rest of the query I can refer to tables just by their name without prepending them with a schema name?

For instance, I would like to do something like this:

    Use [schemaName]
    select * from [tableName]

as opposed to this:

    select * from [schemaName].[tableName]

set default schema for a sql query

Is it possible to use multiple left joins in sql query?

		LEFT JOIN
			ab 
		ON
			ab.sht = cd.sht

i want to add to attach one more query like this to it?
will it work?

		LEFT JOIN
			ab AND aa
		ON
			ab.sht = cd.sht
               AND
            aa.sht = cc.sht

Will this work?

How to use multiple LEFT JOINs in SQL?

I&#39;m hoping to convert a table which has a `DATETIMEOFFSET` field, down to a `DATETIME` field BUT recalculates the time by taking notice of the offset. This, in effect, converts the value to `UTC`.

eg.

    CreatedOn: 2008-12-19 17:30:09.0000000 +11:00

that will get converted to 

    CreatedOn: 2008-12-19 06:30:09.0000000

or 

    CreatedOn: 2008-12-19 06:30:09.0000000 + 00:00 -- that&#39;s a `DATETIMEOFFSET`, but `UTC`.

Cheers :)

How can I convert a Sql Server 2008 DateTimeOffset to a DateTime

I&#39;d really appreciate some help with an SQL query across tables. I realise this sort of thing is asked constantly, but I can&#39;t find a similar enough question to make sense of the answers.

I want to select rows from `table_A` that have a corresponding tag in `table_B`.  
So, for example,  &quot; select rows from `table_a` which are tagged &#39;chair&#39; &quot; would return `table_C`.

Also, `id` is a unique in `table_a`, and not in `table_b`.


    table_A:             table_B:                  table_C:
 
    id    object         id    tag                 id    object
    1     lamp           1     furniture           3     stool
    2     table          2     furniture           4     bench
    3     stool          3     furniture
    4     bench          4     furniture
                         4     chair
                         3     chair

Alternatively, is there a better way to organise the data?


Select from one table matching criteria in another?

I am trying to perform a **Join between multiple tables** in LINQ. I have the following classes:

    Product {Id, ProdName, ProdQty}
    
    Category {Id, CatName}
    
    ProductCategory{ProdId, CatId} //association table

And I use the following code (where `product`, `category` and `productcategory` are instances of the above classes):

    var query = product.Join(productcategory, p =&gt; p.Id, pc =&gt; pc.ProdID, (p, pc) =&gt; new {product = p, productcategory = pc})
                       .Join(category, ppc =&gt; ppc.productcategory.CatId, c =&gt; c.Id, (ppc, c) =&gt; new { productproductcategory = ppc, category = c});

With this code I obtain an object from the following class:

    QueryClass { productproductcategory, category}

Where producproductcategory is of type:
    
    ProductProductCategoryClass {product, productcategory}

I do not understand where the joined &quot;table&quot; is, I was expecting a **single class** that contains all the properties from the involved classes. 

My aim is to populate another object with some properties resulting from the query: 

    CategorizedProducts catProducts = query.Select(m =&gt; new { m.ProdId = ???, m.CatId = ???, //other assignments });

how can I achieve this goal?



                                                   



How to perform Join between multiple tables in LINQ lambda

`SELECT name, price, photo FROM drinks, drinks_photos WHERE drinks.id = drinks_id`  
  
yeilds 5 rows (5 arrays), `photo` is the only unique field in a row. `name, price` get repeated (*here,* `fanta-` `name, price` *repeat 3 times.*)  How do i get rid of these duplicates?  

**Edit:**  I want `name, price` and all `photo` for each drink.

     id      name      price
      1.    fanta        5
      2.     dew         4
   
      
     id      photo                   drinks_id
      1.     ./images/fanta-1.jpg      1
      2.     ./images/fanta-2.jpg      1  
      3.     ./images/fanta-3.jpg      1 
      4.     ./images/dew-1.jpg        2
      5.     ./images/dew-2.jpg        2

SELECT * FROM multiple tables. MySQL

Can someone tell me if there is any difference between

    DROP IF EXISTS [TABLE_NAME]

&lt;!-- --&gt;


    DROP [TABLE_NAME]

I am asking this because I am using JDBC template in my MVC web application. If I use `DROP [TABLE_NAME]` the error said that Table exist. And if I use `DROP IF EXISTS [TABLE_NAME]` it says bad SQL grammar. Can some one help?

DROP IF EXISTS VS DROP?

In MySQL I want to drop a table.  
I tried a lot things but I keep getting the error that the table named `bericht` can&#39;t be dropped. This is the error I&#39;m getting:

&gt;  #1217 - Cannot delete or update a parent row: a foreign key constraint fails

How do I drop this table?

Can&#39;t drop table: A foreign key constraint fails

I want to delete a table using SQLAlchemy.

Since I am testing over and over again, I want to delete the table `my_users` so that I can start from scratch every single time.

So far I am using SQLAlchemy to execute raw SQL through the [engine.execute()][1] method:

    sql = text(&#39;DROP TABLE IF EXISTS my_users;&#39;)
    result = engine.execute(sql)

However, I wonder if there is some standard way to do so. The only one I could find is [`drop_all()`][2], but it deletes all the structure, not only one specific table:

    Base.metadata.drop_all(engine)   # all tables are deleted

---
For example, given this very basic example. It consists on a SQLite infrastructure with a single table `my_users` in which I add some content.

    from sqlalchemy import create_engine, Column, Integer, String, text
    from sqlalchemy.orm import sessionmaker
    from sqlalchemy.ext.declarative import declarative_base
    
    engine = create_engine(&#39;sqlite://&#39;, echo=False)
    Base = declarative_base()
    
    class User(Base):
        __tablename__ = &quot;my_users&quot;
    
        id = Column(Integer, primary_key=True)
        name = Column(String)
    
        def __init__(self, name):
            self.name = name
    
    # Create all the tables in the database which are
    # defined by Base&#39;s subclasses such as User
    Base.metadata.create_all(engine)
    
    # Construct a sessionmaker factory object
    session = sessionmaker()

    # Bind the sessionmaker to engine
    session.configure(bind=engine)

    # Generate a session to work with
    s = session()

    # Add some content
    s.add(User(&#39;myname&#39;))
    s.commit()

    # Fetch the data
    print(s.query(User).filter(User.name == &#39;myname&#39;).one().name)

For this specific case, `drop_all()` would work, but it won&#39;t be convenient from the moment I start having more than one table and I want to keep the other ones.


  [1]: http://docs.sqlalchemy.org/en/latest/core/connections.html#sqlalchemy.engine.Engine.execute
  [2]: http://docs.sqlalchemy.org/en/latest/core/metadata.html#sqlalchemy.schema.MetaData.drop_all

Content Type	Original Author	Original Content on Stackoverflow
Question	Krunal	View Question on Stackoverflow
Solution 1 - Mysql	Leniel Maccaferri	View Answer on Stackoverflow
Solution 2 - Mysql	OrangeDog	View Answer on Stackoverflow
Solution 3 - Mysql	Javaughn Jackson	View Answer on Stackoverflow
Solution 4 - Mysql	user4774666	View Answer on Stackoverflow

Drop multiple tables in one shot in MySQL

Mysql Problem Overview

Mysql Solutions

Solution 1 - Mysql

Solution 2 - Mysql

Solution 3 - Mysql

Solution 4 - Mysql

Why would I want stage before committing in Git?

Android: "Path for project must have only one segment"

Attributions