I have two tables in different databases with different schema, how can I compare them both?
Let's say I have the DB1 with the table history.Table1 and another DB2 with the same table but in a different schema, backup.Table1.
Now I need to compare what's different besides the schema name obviously.
Try SQL Compare from Redgate. They allow you to compare pretty much everything from the actual data to the schema.
I dont believe there is any native functionality in sqlserver.
Compare SQL Server schemas and deploy differences fast
Compare and deploy SQL Server database contents
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)
When I right click on the database I want to export data from, I only get to select a single table or view, rather than being able to export all of the data. Is there a way to export all of the data?
If this is not possible, could you advise on how I could do the following:
I have two databases, with the same table names, but one has more data than the other
They both have different database names (Table names are identical)
They are both on different servers
I need to get all of the additional data from the larger database, into the smaller database.
Both are MS SQL databases
Being that both are MS SQL Servers, on different hosts... why bother with CSV when you can setup a Linked Server instance so you can access one instance from the other via a SQL statement?
Make sure you have a valid user on the instance you want to retrieve data from - it must have access to the table(s)
Create the Linked Server instance
Reference the name in queries using four name syntax:
INSERT INTO db1.dbo.SmallerTable
SELECT *
FROM linked_server.db.dbo.LargerTable lt
WHERE NOT EXISTS(SELECT NULL
FROM db1.dbo.SmallerTable st
WHERE st.col = lt.col)
Replace WHERE st.col = lt.col with whatever criteria you consider to be duplicate values between the two tables.
There is also a very good tool by Redgate software that syncs data between two databases.
I've also used SQL scripter before to generate a SQL file with insert statements that you can run on the other database to insert the data.
If you right-click on the database, under the Tasks menu, you can use the Generate Scripts option to produce SQL scripts for all the tables and data. See this blog post for details. If you want to sync the second database with the first, then you're better off using something like Redgate as suggested in mpenrow's answer.
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
I have a need to access data in a MS SQL database from within in MySQL and would like to know my options. The data is held across various joined tables
Ideally I would like to mirror the database schema and data in MySQL so that it can be queried from within Wordpress.
The data is hotel information as seen here http://www.vrxstudios.com/advanced_search.aspx
The plan is to represent each hotel as a wordpress post.
Would it make sense to create a flat table in SQL and link this somehow in MySQL?
Any help gratefully received.
Thanks
Jonathan
If you want to move data from MS SQL Server to MySQL you could use SSIS routines to move the data. You could schedule the data import to happen as often has you need.
The simplest form would be a direct copy in schema structure from MS SQL Server.