In SQLite FTS tables there is a hidden languageid column that I want to make use of: I need to populate my FTS4 table with rows in two different languages, which I will then distinguish by languageid column.
I create my table with a command like this:
CREATE VIRTUAL TABLE `texts` USING FTS4(`text`, tokenize=unicode61, languageid=`lid`)
Now how can I INSERT a row with a specified languageid if it is a hidden column? Or is there some other way to specify the language used in a row?
So, I had to explicitly specify the languageid column like this (here lid is the name of languageid column):
INSERT INTO `texts` (`text`,`lid`) VALUES (?,?)
Sidenote: I used Python in IntelliJ IDEA for this and the IDE gave me a Unable to resolve column 'lid' error, but the code still worked.
Related
I searched but only could found partial answer to this question
The goal would be here to create a new ID column on an existing table.
This new column would be the primary key for the table and I simply want it to be filled with integer values from 1 to number of rows.
What would be the query for that?
I know I have to first alter table to create the new column :
ALTER TABLE <MYTABLE> ADD (ID INTEGER);
Then I could use the series generator :
INSERT INTO <MYTABLE.ID> SELECT SERIES_GENERATE_INTEGER(1,1,(number of rows));
Once the column is filled I could use this line:
ALTER TABLE <MYTABLE> ADD PRIMARY KEY ("ID");
I am sure there is an easier way to do this
You wrote that you want to add a "new ID column to an existing table" and fill it with unique values.
That's not a "standard" operation in any DBMS, as the usual assumption is that records are created with a primary key and not retro fitted.
Thus, "ease" of operation for this is relative to what else you want to do.
For example, if you want to continue using this ID as a primary key for further operations, then using a once-off generator function like the SERIES_GENERATE_INTEGER or a query won't be very helpful since you have to avoid duplicates of already existing values.
Two, relatively easy, options come to mind:
Using a sequence:
create sequence myid;
update <table> set ID = myid.nextval;
And for succeeding inserts:
insert into <table> (id, ..., ...) VALUES (myid.nextval, ..., ...) ;
Note that this generates a value for every existing record and not a predefined set of size X.
Using a GUID
By using a GUID you generate a unique value every time you call the 'SYSUUID' function in SAP HANA. check docu here
Something like
update <table> set ID = SYSUUID;
should do the trick here.
Subsequent inserts would simply call the function for values of ID.
Application has different versions. Each version has it's own set of values in each table. I need to provide functionality to copy data from one version to another. Problem :
By inserting data I am trying to insert Ids which has already been in use in this table. So, I need to change ids of components which I want to insert but I must save relationship between those components. How cat I do that?
Create a master table which has a surrogate key as your primary key. A numeric value of type NUMBER(9) works well. You can create a sequence and trigger to automatically insert this.
The rest of the table is the column of your current table plus a column to indicate which version the row is for.
For simplicity you may wish to create views on top of the table along the lines of
select * from master_table where version_id = ####;
To copy the data from one version to another this will work:
Insert into master_table seq_master_table.nextval, new version_id,.....
from master_table
where version_id = ####;
I have a database name "EmpOld" with a table name "Employee" and a database name "EmpNew" with a table name "Employee".
The table structures are identical on both database tables except for the names in the table.
Here is a definition of the tables:
Database "EmpOld" table name "Employee" has following field names:
int e_id
char(20) e_fname
char(25) e_lname
Database "EmpNew" table "Employee" has following field names:
int id
char(20) fname
char(25) lname
Notice, the only difference in the tables is the "e_" prefix for field names are removed from the EmpNew Employee table.
How do I move data from EmpOld database to EmpNew database?
Is there a code that maps these field respectively.
Thanks community,
Nick
Well, you could just name them manually:
INSERT dbo.EmpNew(fname, lname) SELECT e_fname, e_lname FROM dbo.EmpOld;
If you want to do this without manually typing out the column names, there is magic in SSMS - just drag the Columns folder from each table into the appropriate spot in your query window (and then manually remove identity columns, timestamp, computed columns etc. if relevant).
There is no automatic way of mapping fields, unless with some code.
This can be done in two ways:
Using the SQL Import & Export Wizard
This is the most easy way to do this and here is an article that gives step by step to do this. The key is to change the mapping between the source and destination fields while importing the data.
Writing an SQL
This method requires both the databases to be accessible. Using a simple insert statement as follows this can be achieved
insert into EmpNew.dbo.Employee(id, fname, lname)
select
e_id, e_fname, e_lname
from
EmpOld.dbo.Employee
If they are on same sql server then the above will work good as is. If they are different sql server you may have to add a link server connection and prefix the table commands with that.
Is there a code that maps these field respectively.
No - you'll need to provide the mapping. If you're using an ETL tool like SSIS there may be a way to programatically map columns based on some criteria, but nothing built into SQL.
Maybe you can generate code with help from the tables sys.columns and other system tables so that you can make the copy-process run automatically.
I think you can't use:
insert into (...) (...)
because you have two databases. So just generate insert statements like:
insert into table (...) VALUES (...)
Please correct me if i misunderstood the question.
There are 2 ways you can do without the data loss.
1) you can use Insert statement
`
Insert into EmpNew (ID,fname,lname)
Select e_id, e_fname, e_lastname
from EmpOld
`
2) You can simple use Import-Export Wizard
Go to Start Menu > SQL Server 2008/2008R2/2012 > ImportandExport>
This will take you the wizard box
Select Source :- DataSource(ServerName) and Database where you are
extracting data from
Select Destination : DataSource(ServerName) and Database where you are extracting data to
Map the table
BE AWARE of PK/FK/Identity
you are good to go
I just started working with SQL Server and I have some troubles with adding values to a table with a column of type uniqueidentifier.
The table consists of:
ID (uniqueidentifier), CODE (nchar(5)), COUNTRY_CODE(nchar(2)), NAME(nchar30)
I tried adding values from Excel and CSV files, basically they look like this:
DEBE,DE,Berlin
I could not load it, always have some errors with this ID field.
When i try to add values manually like:
INSERT INTO [Portfolio].[dbo].[Regions](CODE, COUNTRY_CODE, NAME)
VALUES ('DEBE', 'DE', 'Berlin');
It says:
Cannot insert the value NULL into column 'ID', table
'Portfolio.dbo.Regions'; column does not allow nulls. INSERT fails.
Of course when I add an id column and a number, I get info that int is incompatible with uniqueidentifier.
I even tried creating a temp table (with id as an INT instead of uniqueidentifier) and copying values from it into this (without ID column, its supposed to generate automatically)
Only thing I can think of is that ID column is not creating values for it automatically and I don't know how to solve this. Can anyone help?
Uniqueidentifier is a special type you can use to generate GUID. Is 16 byte long and is not incremented automatically as the Identity columns. You need to use Convert or Cast clause in order to get the correct uniqueidentifier from a varchar, if it exceeds the 16bytes it will be truncated.
Use NewID() to generate a new uniqueidentifier.
Maybe this link can help you
As mentioned above, use NewID() to create an identifier.
When you are in the design mode for the table, NewID() can be placed in the 'Default Value or Binding' slot. This means that for any new record that you insert into the table (such as CODE, COUNTRY_CODE, NAME), a Unique Identifier will be created.
What I think you are looking for is an Identity field. The UniqueIdentifier field is used for storing GUID's.
Change the field type to int and then change it's Identity Specification to 'Yes".
The other solution would be to pass the ID field your own GUID from code.
Too late to answer, but it may help someone, go to you sql table design mode,
select your required table's attribute, here in detail tab (down to table) you'll see a property
RowGuid --> Yes (make sure to turn it to yes).
Cheers :)
I am using a Sybase database and would like to know if it's valid to have a table contain a column with the same name as that of the table, e.g.:
CREATE TABLE foo
(
foo int not null,
etc...
)
Valid? Sure. Recommended? No.
Yes, we can surely do that but as said it is not recommended. But why are we able to do so? Well, because a table name entry goes into the system table sysobjects however column entries go in the system table syscolumns.
Therefore there is no restriction in using table name as column name, however using table name as column name usually is not recommended because it makes your table structure a bit confusing and also it adds bad practice to database design.