Im going to create a design for an application that looks like a Google drive, anyone can create files on the root directory or creating inside folders (and subfolders)
Now on the user's console, I have to show all the top level folders, a down arrow will be there, it the folder contains any subfolder, then if we click the down arrow, all the subfolders inside the folder will be visible.
Sample:
Im not sure, what kind of Table design I should choose for this, can someone help me with this?
You can create a self referencing hierarchical table for that. There will be parent_id column to store the id of parent folder. For top level folder parent_id will be null.
Below can be the list of columns for your table.
1. id -- integer auto increment primary key.
2. Name -- Name of the folder
3. Parent_id -- id of parent folder. Referencing id column of this table. Null for top level folders.
4. Sequence_Number -- In which sequence folders will be displayed. Folder with same parent_id will be displayed order by seqeunce_number. You can change it from front end so that user can choose to rearrange folder sequence.
5. description -- description of a folder. If you want to put it.
6. user_id -- Foreign key to user table.
I want to backup existing table storage 1:1 to new table storage. Be default I have to manually select tables, and on next page I have to manually set the name to existing one. How to make it automatic? See the screenshots:
Event if Select all is ticked, if new table appears later, it won't be included
Every table has a TableX name, I want them to have the same names like in source
There isn't a event trigger for table storage that when an new table created.
I would suggest you still use Select all option. Then create a schedule trigger to run the pipeline. That's a way to 'sync' the data between Table Storage 1 and 2. If your Table Storage is not very large, it could be a good way.
HTH.
I am trying to load data from S3 bucket to redshift table,there is one column as source id in the table and i want to store the folder name where the source file is available,in to that column.
Actually i have multiple folders in S3 bucket and in each folder i have one file and i port all the files in same table with copy command in redshift, so to identify from which folder the data is, so i need to store the folder name along with data into the Redshift table, i have seperate column in table as Source id.
can any body help me.
If you are using the Redshift copy command, then you have no choice other than a process to import each folder (e.g. as a temp table) and then set your value manually the the value of the folder that you restored. repeat for each folder.
Another option is to use redshift spectrum and create an external table that maps to your folder as partitions.
first you create your base table like this
create external table spectrum.sales_part(
salesid integer,
listid integer,
sellerid integer,
buyerid integer,
eventid integer,
dateid smallint,
qtysold smallint,
pricepaid decimal(8,2),
commission decimal(8,2),
saletime timestamp)
partitioned by (saledate date)
row format delimited
fields terminated by '|'
stored as textfile
location 's3://awssampledbuswest2/tickit/spectrum/sales_partition/'
table properties ('numRows'='172000');
Then you add partitions to it like this
alter table spectrum.sales_part
add partition(saledate='2008-01-01')
location 's3://awssampledbuswest2/tickit/spectrum/sales_partition/saledate=2008-01/';
alter table spectrum.sales_part
add partition(saledate='2008-02-01')
location 's3://awssampledbuswest2/tickit/spectrum/sales_partition/saledate=2008-02/';
alter table spectrum.sales_part
add partition(saledate='2008-03-01')
location 's3://awssampledbuswest2/tickit/spectrum/sales_partition/saledate=2008-03/';
Once you have that set up as an external table, you can use standard sql against that table, for example you could run your queries against that table or copy it to a permanent redshift table using CTAS.
Here is a link to the documentation
https://docs.aws.amazon.com/redshift/latest/dg/c-spectrum-external-tables.html
I am doing some databese thing, I need copy one table from one model to another, but i try many ways there no effect.
Is there any way for doing this?
If you just want to do a single table through the MySQL Workbench.
In MySQL Workbench:
Connect to a MySQL Server
Expand a Database
Right Click on a table
Select Copy To Clipboard
Select Create Statement
A create statement for the table will be copied to your clipboard similar to the below:
CREATE TABLE `cache` (
`cid` varchar(255) NOT NULL DEFAULT '',
`data` longblob,
`expire` int(11) NOT NULL DEFAULT '0',
`created` int(11) NOT NULL DEFAULT '0',
`headers` text,
`serialized` smallint(6) NOT NULL DEFAULT '0',
PRIMARY KEY (`cid`),
KEY `expire` (`expire`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8;
Create the table in the new database
Open a new SQL tab for executing queries (File->New Query Tab)
Alter the create table code to include the database to create the table on.
CREATE TABLE `databaseName`.`cache` (
`cid` varchar(255) NOT NULL DEFAULT '',
`data` longblob,
`expire` int(11) NOT NULL DEFAULT '0',
`created` int(11) NOT NULL DEFAULT '0',
`headers` text,
`serialized` smallint(6) NOT NULL DEFAULT '0',
PRIMARY KEY (`cid`),
KEY `expire` (`expire`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8;
Then click the Execute button (looks like a lightening Bolt)
That will copy the table schema from one db to another using the MySQL workbench. Just refresh the tables in the database and you should see your newly added table
Select tab with source database
In menu: Server->Data Export
Select Schema and the Table as Schema Object
Select option Export to Self-Contained File and check Create Dump in a Single Transaction (self-contained only)
Copy full file path to clipboard
Start Export
Select tab with target database
In menu: Server->Data Import. Make sure your target database name is at the top left corner of the Data Import view
Select Import from self contained file and paste full file path from clipboard
Select Default Target Schema
Select Dump Content (Dump Structure and Data etc…)
Start Import
Your best option is probably to create a stripped down version of the model that contains the objects you want to carry over. Then open the target model and run File -> Include Model.... Select the stripped down source model and there you go.
You can just use a select statement. Here I am creating a duplicate of "original_table" table from the "original_schema" schema/database to the "new_schema" schema :
CREATE TABLE new_schema.duplicate_table AS
Select * from original_schema.original_table;
You can just put any select statement you need ,add a condition and select the columns :
CREATE TABLE new_schema.duplicate_table AS
SELECT column1, column2
FROM original_schema.original_table
WHERE column2 < 11000000;
I think it is worth mentioning that
a copied table may reference fields in tables of the original schema, that do not exist, in the schema where it's to be copied. It might be a good idea, to inspect the table for these discrepancies, before adding it to the other schema.
it's probably a good idea, to check engine compatibility (e.g. InnoDB vs MyISAM) and character set.
step 1 : Righit click on table > copy to clipboard > create statement
step 2: paste clipboard in the query field of workbench.
step 3: remove (``) from the name of the table and name of the model(schema)followed by a dot.
eg : `cusine_menus` -> schema_name.cusine_menus
execute
If you already have your table created and just want to copy the data, I'd recommend using the "Export Data Wizard" and "Import Data Wizard". It is basically choosing stuff in the program for exporting and then importing the data and is easy to use.
MySQL has an article on the wizards here: Table Data Export and Import Wizard
To copy data using the wizards, do the following:
Find the table in the list from which you want to copy data from.
Right click and choose "Table Data Export Wizard."
Choose the columns you wish to copy.
Choose a location to save a *.csv or *.json file with the copied data.
Find the table to insert the copied data to.
Right click and choose "Table data import wizard".
Choose the file you just exported.
Map the columns from the table you copied from to the table you insert to.
Press "Finish". The data is inserted as you chose.
In this post, we are going to show you how to copy a table in MySQL
First, this query will copy the data and structure, but the indexes are not included:
CREATE TABLE new_table SELECT * FROM old_table;
Second, this query will copy the table structure and indexes, but not data:
CREATE TABLE new_table LIKE old_table;
So, to copy everything, including database objects such as indexes, primary key constraint, foreign key constraints, triggers, etc., run these queries:
CREATE TABLE new_table LIKE old_table;
INSERT new_table SELECT * FROM old_table;
If you want to copy a table from one database to another database:
CREATE TABLE destination_db.new_table LIKE source_db.old_table;
INSERT destination_db.new_table
SELECT
*
FROM
source_db.old_table;
create table .m_property_nature like .m_property_nature;
INSERT INTO .m_property_nature SELECT * from .m_property_nature;
You can get the crate table query from table info and use the same query on different database instance.
show create table TABLENAME.content and copy the query;
Run the generated query on another Db instance connected.
I am using Eclipse, Java and a Derby database. I want to experiment with changing values that rewrite one of the tables in the db. Before starting the change I would like to copy the particular table (not in code) so that I can restore the original data if necessary. Sof ar googling and searching this site hasnt produced an answer. In Eclipse there is an option to export the db but it calls it a connection so I am not usre what would happen.
If you're not sure about how to connect to the database and issue sql statements, you will need to learn about JDBC. This is a good place to start.
If you're asking about the SQL, it's pretty straight forward. You can create a table based on a select statement.
e.g.
create table table2 as select * from table1 with no data;
Derby is a little strange in this area. You must specify the with no data, and the created table will be empty. You can then issue an insert that will populate the new table if you wish.
insert into table2 select * from table1;
The new table will not have indexes. You will need to create them if you want them. It might retain the primary key. You should check that if you're testing against it. If it doesn't retain the primary key, you should create the primary key before inserting data into the table.
In Eclipse there is an option to export the db but it calls it a connection so I am not sure what would happen.
If what Eclipse does isn't clear for you, you can just as well zip your entire database directory (content of DERBY_HOME env. variable) into an archive. The database must not be running while you make the backup.