I have created a table with some columns using PL/SQL Develper to access this Oracle database.
After clicking the "Apply" button that will create the table, all my column names suddenly become upper case (which can hardly be read), including the table name!
Would that be possible to configure PL/SQL Developer IDE to leave the columns names and table names as they are?!
Oracle DBMS ignores case and translates everything to uppercase unless you use quotes. But the quotes have the liability that you always have to use them.
If you do not use the quotes you will get an error message ORA-00942: table or view does not exist
You can give column name in double quote "". Then those column name will be in as it is.
Related
I'm using DBeaver to write script for my PostgreSQL database.
I have a PostgreSQL DB with Tables autogenerated by C#/EFCore (Microsoft ORM) - I receive SQL Error [42P01] if I don't add double quotes around table names when I cut and paste my ORM queries to DBeaver. I got [42703] for fields without double quotes. I do not have to add double quotes in C# code but it appears to be required in DBeaver?
example:
select * from Dnp3PropertyBase => SQL Error [42P01]
select * from "Dnp3PropertyBase" => OK, all results shown...
Does anybody know if I can change a parameter in DBeaver somewhere in order to enter table names and fields without double quotes?
Note: Using DBeaver 22.3.2 (latest on 2023-01-11)
Update After reading: Postgresql tables exists, but getting "relation does not exist" when querying
show search_path => public, public, "$user"
SELECT * FROM information_schema.tables => All tables are in public schema
SELECT * FROM information_schema.columns => All columns are in public schema
Question: How to be able to cut and paste my EFCore generated queries from Visual Studio output window to DBeaver query without having any errors regarding table names and field names?
First let me copy #a_horse_with_no_name comment:
Unquoted names are folded to lower case in Postgres (and to uppercase
in Oracle, DB2, Firebird, and many others). So SomeTable is in fact
stored as sometable (or SOMETABLE). However quoted identifiers have to
preserve the case and are case sensitive then. So "SomeTable" is
stored as SomeTable
Many peoples recommended me to go with snake case which I didn't want to go with initialy because all tables were auto generated by EF Core (Microsoft C# ORM). I told myself that Microsoft would do standard things. Microsoft use the exact "class" name in code as the table name , by default. That appears to me very logical in order to stay coherent and apply the same rules everywhere. C# recommended to use Camel case for classes so each table names end by default in Camel case instead of snake case.
PostgreSQL seems to promote users to use snake casing because they lower case every non double quoted names. According to a_horse_with_no_name, and I think the same, only PostgreSQL has the behavior of lower casing down every table names and field names which are not double quoted in SQL script. That behavior (changing casing for non double quoted names) appears to me as being very limitative. It also has hidden effect that could be hard to find for non initiated peoples coming from other DB world.
According to PostgreSQL doc, they recommend to use nuget package (.UseSnakeCaseNamingConvention()). It probably works fine for TPH (table per hierarchy) which is recommended by Microsoft for performance. But it does not works for table name for TPC (table per class) because of actual bugs in EFCore 7 (see Github project).
I received that message at the end of "update-database":
Both 'WindTurbine' and 'ResourceGenerator' are mapped to the table
'resource_generator'. All the entity types in a non-TPH hierarchy (one
that doesn't have a discriminator) must be mapped to different tables.
See https://go.microsoft.com/fwlink/?linkid=2130430 for more
information.
PostgreSQL doc : TPH supported OK but not for table in TPC (2023-01-12). I use TPC then I had to force each table name directly through TableAttribute.
My solution For table name, I use snake casing by manually add a "Table" attribute to each of my classes with the proper name like this sample:
[Table("water_turbine")]
public class WaterTurbine : ResourceGenerator
For fields, I use the EFCore.NamingConventions NugetPackage which works fine for fields names. Don't forget that if you have 2 classes mapped to the same object, it is because you are using TPC and did not force table name through TableAttribute.
This way all my table and fields names are snake casing and I can cut and paste any query dumped in my debugger directly in any SQL script window of DBeaver (or any SQL tool).
Is there any way I can create a mixed case table name in Oracle without using quotes?
The table names change to uppercase if I do not use quotes while creating the table.
Let me know if you need more information.
Eg:
create table testTable(testColumn varchar);
This creates a table named TESTTABLE with column name TESTCOLUMN.
I can use quotes, but it makes it more messy and difficult to write queries.
Can you please let me know how I can do this without using quotes? Thanks.
Regards,
Sawan
Please refer to the official Oracle Database documentation:
"Nonquoted identifiers are not case sensitive. Oracle interprets them as uppercase."
https://docs.oracle.com/en/database/oracle/oracle-database/20/sqlrf/Database-Object-Names-and-Qualifiers.html#GUID-3C59E44A-5140-4BCA-B9E1-3039C8050C49
All the data dictionary views will show the identifiers as Oracle interprets them. In other words, without quotes everything will be uppercase. I can testify that this is true even for accented characters.
You can't always get what you want...
I am trying to find an easy way to remove columns/fields from an existing QGIS Spatialite database file. I am new to both Spatialite GUI and SQL, but I want to get the said job done. I right-clicked on a layer (for-China) and chose 'Show columns' from the context menu. Then I got an error message:
SQL error: "near "-": syntax error"
so I tried executing the statement:
PRAGMA table_info('for-China');
alter table 'for-China'
delete row 'note';
and the table showed up, but the NOTE row wasn't deleted:
I tried using COLUMN instead of ROW and also tried using DROP instead of DELETE but NOTE is still left untouched. I am confused on what to do to delete the NOTE row.
I assume that spatialite uses the same escape characters as SQLite. Hence, try double quotes:
PRAGMA table_info("for-China");
alter table "for-China" drop column note;
You should only need this for identifiers that are keywords or use characters other than alpha numeric, underscore (and perhaps a few others).
SQLite also recognizes backticks and square braces, as explained in the documentation.
I was trying to use sqlFetch. The fetch works perfectly when I change the name of my table to have underlines instead of periods. So if I use the command
sqlFetch(conn, "HelloWorld_40")
It works fine. Unfortunately, my friends are all using the real name of the table
sqlFetch(conn, "HelloWorld.40")
But then it crashes and it tells me that
Error in sqlColumns(conn, "HelloWorld.40") :
'HelloWorld.40': table not found on channel
I'm guessing the period "." is illegal name for a table. But I don't want my friends to change it because it's a lot of people who would be affected. Is there a way I can call the table, or do I have to secretly go to their database, change the name while I use it and then change it back to a period (risking that I will forget, someone will read, blah blah).
Thanks.
put the table name in square brackets:
[HelloWorld.40]
It is a problem with sqlFetch which parse table name. Unfortunately it did not handle table quotes, so it's search for table 40 in schema HelloWorld. You need to directly call sqlQuery (with quoted table name, brackets for MS SQL Server):
sqlQuery(dbhandle, "SELECT * FROM [HelloWorld.40]")
Side note: you should specify which database you are using.
The best delimiter is double quotes -- that should work in most underlying databases:
"HelloWorld.40"
In MySQL, you can also use back ticks (`):
`HelloWorld.40`
In SQL Server, Access, and I think Sybase, you can also use square braces:
[HelloWorld.40]
I am trying to run this update statement but informix doesn't allow me to.
I have a table, named ITEMS and below I have selected some records from it.
SELECT SHORT_SKU, ITEMS."STYLE" FROM ITEMS;
SHORT_SKU STYLE
--------- -----
01846173 null
01811752 null
01811748 null
Trying to run the below UPDATE statement, informix says syntax error.
UPDATE ITEMS SET ITEMS."STYLE" = 'M' WHERE SHORT_SKU = '01846173';
^ syntax error here
Then I changed (as below) and got "Column (style) not found in any table in the query (or SLV is undefined)."
UPDATE ITEMS SET STYLE = 'M' WHERE SHORT_SKU = '01846173';
How do I update the "STYLE" field?
UPDATE 1
I did a change to one of WAS data source's custom properties, ifxDELIMIDENT. Originally it was blank. So, I changed it to true. Restarted WAS. And I couldn't login to our application. SQLExceptions were thrown by WAS but was not able to see the stack trace because WAS has truncated the last few lines. After changing the property back to blank, I was able to login to our application.
I tried another approach, which was to write a Java class that updates the ITEMMST.STYLE column. I executed this from a shell script. In the shell script, I defined and exported the variable DELIMIDENT with the value 'Y'. But I am still getting 'Syntax error'.
UPDATE 2
I managed to update the column. This is done by adding the 'DELIMIDENT=Y' property at the end of the connection string which will be passed to the DriverManager object when opening the database connection.
But, this won't work for our web application because it uses the WebSphere data source to create the db connection. It would be super if there's a way to set this property in the Informix environment itself.
Try:
UPDATE ITEMS SET "STYLE" = 'M' WHERE SHORT_SKU = '01846173';
It must be that STYLE is a reserved word so you must double-quote it to refer to the column. But standard UPDATE syntax doesn't allow you to prefix column names with the table name in the SET clause (since you can only be updating the columns of one table: the table mentioned in the UPDATE).
The right Syntax would be
UPDATE ITEMS SET STYLE = 'M' WHERE SHORT_SKU = '01846173';
As stated on IBM Documentation but as STYLE is a reserved word i guess your getting problems, Read IBM Recommendation on this.
Anyway you may find a work arround oat this link, otherwise you may consider changing the column name.
I am not aware of STYLE being a keyword in Informix (but I haven't gone to look for it). However, you can usually use keywords as column names etc without much problem.
If you must quote it, you need to set the DELIMIDENT environment variable - the value doesn't matter, but use DELIMIDENT=1 for concreteness. This enables SQL standard 'delimited identifiers', where double quotes surround identifiers (column names, table names, etc) and single quotes surround strings. (Normally, you can use either single quotes or double quotes around strings.)
One other point: if you use delimited identifiers, they also become case-sensitive (whereas normally, identifiers are case-insensitive). So you need to know how the STYLE column is stored in the system catalog. In most databases, they will be in lower-case. There's an outside chance that in a MODE ANSI database, they are stored in upper-case (but it is a while since I looked to make sure).
Use this query:
UPDATE ITEMS SET ITEMS.STYLE = 'M' WHERE SHORT_SKU = '01846173';
I think double quotes not required for column name.
Updated Answer 1:
Error Description-
-217 Column column-name not found in any table in the query
(or SLV is undefined).
The name appears in the select list or WHERE clause of this query but is
not defined in a table and does not appear as a statement local variable
(SLV) definition. Check that the column name or SLV name and the names of
the selected tables are spelled as you intended.
If all names are spelled correctly, you are not using the right tables,
the database has been changed, or you have not defined the SLV. If the
name not found is a reference to a column, that column might have been
renamed or dropped. If the name not found represents an SLV and you
defined the SLV in the statement, make sure that the SLV definition
appears before all other references to that SLV name.
This error message can also appear during the execution of an ALTER TABLE
statement when the engine tries to update views that depend on the table.
More info link
Updated Answer 2:
If not possible to change column name then get more information about SLV.
You can refer following links for description and use of SLV:
link1
link2
link3
There are 2 solutions for this.
Set the Informix JDBC data source 'ifxDELIMIDENT' property to 'true'
Rename the affected table columns
For the 1st option, we had a problem after setting the data source to 'true'. Suddenly all our queries did not work. After much troubleshooting, we found out that by setting the 'ifxDELIMIDENT' property to 'true', it also changed Informix to be case sensitive. In our Java code, we have all the column names in uppercase, and in Informix (Example: resultSet.getString("STYLE")), but the table column names are lowercase (Example: 'style'). This was why after changing this property, we were not able to login to our application Unfortunately this behavior was not documented anywhere in IBM's Info Centre nor in the internet.
We opted for the 2nd option which involved changing the affected column names to another column name (Example: Changed 'STYLE' to 'ITEM_STYLE').