I have a database called AQOA_Core with huge amount of data.
I have a newly created database called AQOA_Core1 which is basically empty. I want to write a query to duplicate AQOA_Core to AQOA_Core1 without the data. I guess to be precise I want to create a skeleton of the primary database into the secondary database.
PS: I use Toad for my database operations.
You can use SQL Server Script Wizard for scripting database objects. You can exclude data, and select the database object types you want to include in your script
Please check the SQL Server guide I referenced above,
I hope it helps you
I don't know if I am using the correct terminology here.
I want to recreate the tables of a local database on my computer on another one. I do not care about duplicating the data stored, but just the tables, their relationships, constraints etc.
I have been using Microsoft SQL 2012. Is there a way to generate the SQL code that defines my tables. (What I would have typed to set up my tables had I not done it graphically)
I need some data of one db and some data of another db and perform some operation. Can we do this in sql server 2008? In my project suppose I want to fetch data of doctor and Chemist database in CRM Database and want to generate operation, How can we do that?
If both db belongs on the same sql server instance you can use full qualified names of objects like [DbName].[scheme].[table] if on different instances then you must create linked server. Of course, providing access as expected.
Taking a peek into the information_schema database and peeking at the metadata for one of my pet projects, I'm having a hard time understanding what (if any) differences there are between the create schema command and the create database command for MySQL.
Are there any differences? If not, is this a rather typical pattern of behavior for relational databases (I've heard that for other databases, such as Oracle, a schema exists in a database, rather than being on the same level as a database).
Thanks!
The documentation of MySQL says :
CREATE DATABASE creates a database
with the given name. To use this
statement, you need the CREATE
privilege for the database. CREATE
SCHEMA is a synonym for CREATE
DATABASE as of MySQL 5.0.2.
So, it would seem normal that those two instruction do the same.
Mysql documentation says : CREATE SCHEMA is a synonym for CREATE DATABASE as of MySQL 5.0.2.
this all goes back to an ANSI standard for SQL in the mid-80s.
That standard had a "CREATE SCHEMA" command, and it served to introduce
multiple name spaces for table and view names. All tables and views were
created within a "schema". I do not know whether that version defined
some cross-schema access to tables and views, but I assume it did.
AFAIR, no product (at least back then) really implemented it, that whole
concept was more theory than practice.
OTOH, ISTR this version of the standard did not have the concept of a
"user" or a "CREATE USER" command, so there were products that used the
concept of a "user" (who then had his own name space for tables and
views) to implement their equivalent of "schema".
This is an area where systems differ.
As far as administration is concerned, this should not matter too much,
because here you have differences anyway.
As far as you look at application code, you "only" have to care about
cases where one application accesses tables from multiple name spaces.
AFAIK, all systems support a syntax ".",
and for this it should not matter whether the name space is that of a
user, a "schema", or a "database".
Strictly speaking, the difference between Database and Schema is inexisting in MySql.
However, this is not the case in other database engines such as SQL Server. In SQL server:,
Every table belongs to a grouping of objects in the database called database schema. It's a container or namespace (Querying Microsoft SQL Server 2012)
By default, all the tables in SQL Server belong to a default schema called dbo. When you query a table that hasn't been allocated to any particular schema, you can do something like:
SELECT *
FROM your_table
which is equivalent to:
SELECT *
FROM dbo.your_table
Now, SQL server allows the creation of different schema, which gives you the possibility of grouping tables that share a similar purpose. That helps to organize the database.
For example, you can create an schema called sales, with tables such as invoices, creditorders (and any other related with sales), and another schema called lookup, with tables such as countries, currencies, subscriptiontypes (and any other table used as look up table).
The tables that are allocated to a specific domain are displayed in SQL Server Studio Manager with the schema name prepended to the table name (exactly the same as the tables that belong to the default dbo schema).
There are special schemas in SQL Server. To quote the same book:
There are several built-in database schemas, and they can't be dropped or altered:
1) dbo, the default schema.
2) guest contains objects available to a guest user ("guest user" is a special role in SQL Server lingo, with some default and highly restricted permissions). Rarely used.
3) INFORMATION_SCHEMA, used by the Information Schema Views
4) sys, reserved for SQL Server internal use exclusively
Schemas are not only for grouping. It is actually possible to give different permissions for each schema to different users, as described MSDN.
Doing this way, the schema lookup mentioned above could be made available to any standard user in the database (e.g. SELECT permissions only), whereas a table called supplierbankaccountdetails may be allocated in a different schema called financial, and to give only access to the users in the group accounts (just an example, you get the idea).
Finally, and quoting the same book again:
It isn't the same Database Schema and Table Schema. The former is the namespace of a table, whereas the latter refers to the table definition
CREATE SCHEMA is a synonym for CREATE DATABASE. CREATE DATABASE Syntax
Database is a collection of schemas and schema is a collection of tables. But in MySQL they use it the same way.
So, there is no difference between MySQL "database" and MySQL "schema": these are two names for the same thing - a namespace for tables and other DB objects.
For people with Oracle background:
MySQL "database" a.k.a. MySQL "schema" corresponds to Oracle schema.
The difference between MySQL and Oracle CREATE SCHEMA commands is that in Oracle
the CREATE SCHEMA command does not actually create a schema but rather populates it
with tables and views.
And Oracle's CREATE DATABASE command does a very different thing than its MySQL counterpart.
there is no difference between MySQL "database" and MySQL "schema": these are two names for the same thing
How to create a dynamic SQL statement, that will update any table given as one of parameter. Here I believe, i couldn't use "Set Column1 = Value ....." as the columns will differ according to the table.
This is an extremely poor idea. You can create massive havoc with your database doing such a thing. I can't imagine any dba who would allow it. You need to know the specifics of a table to insert into it properly, you need to be aware of what fields are required and what fields have default values. You need to know what kind of information and data types should be in each field so that you do not send bad data to the database. One proc that does all cannot properly check these things and certainly can't ever be properly tested. Further it means permissions must be at the table level which is a poor choice for internal security as well as for SQL injection attacks.
Could you provide more context? Are you executing arbitrary SQL statements from within scripts, such as Perl, PHP, or Python? Are you just trying to get a command-line .sql script working? What database server are you working on?
The solution can vary widely depending on your situation.