I have recently moved a database from Sql Server 2000 to Sql Server 2005. In the table designer, it insists on putting square brackets around a column named "Content" I don't see Content on the list of reserved words for Sql Server, so I don't understand why it is doing this. Is there a way I can prevent it?
CONTENT is a keyword when defining an XML column with a schema.
See here.
Edit: The MSDN link is broken (per Champ's comment), so here is the relevant extract:
Creating a typed XML column is as simple as adding the name of the schema inside parentheses, as you see here:
CREATE TABLE Foo(FooID INT, someXml XML(CONTENT FooSchema))
This statement indicates that the someXml column must adhere to the XML Schema Collection named FooSchema. You can specify that the XML must be a document or that it can contain a fragment by including the appropriate keyword, DOCUMENT or CONTENT, respectively. If omitted, the default is CONTENT.
The problem is that the field has the same name as the table. Sql Server 2000 did not seem to care about this potential ambiguity, but Sql Server 2005 does. When I add a field named Content to a table that is not named Content, the square brackets do not appear.
pamela
No, you can't prevent it. You can always add square brackets around a column name so it doesn't hurt anything.
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).
Can anybody tell me what does the error mean? Whenever I open the query builder it will prompt with an error indicating that SQL syntax errors were encountered.
https://msdn.microsoft.com/en-us/library/ms189012.aspx
I looked at the following page in MSDN but I don't understand what it means...
For instance, what do these bullet points from the MSDN article mean?
The SQL statement is incomplete or contains one or more syntax errors.
The SQL statement is valid but is not supported in the graphical panes (for example, a Union query).
The SQL statement is valid but contains syntax specific to the data connection you are using.
USER (which you've apparently decided is an appropriate table name) is a SQL Server reserved word.
The best solution is to rename your table, so you don't have to escape the table name every time you want to query it and to make it clear it's your user data (hey, there's a table name suggestion - userdata).
The other option is to escape the name by surrounding it with square brackets:
SELECT * FROM [users]
Note that it will get old fast having to do this with every query. Again, the best solution would be to rename the table to something that isn't a reserved word.
I have been using SQL Server CE for a while. In that database the table names were like
UserPosts, UserProfile.
But after my upgrade from SQL Server CE to SQL Server the names are edited to dbo.UserPosts, dbo.UserProfile. And also the names of columns are wrapped in square brackets like: [UserProfile].
Why is this bracket used?
Brackets are used to surround names in SQL Server (they server the same purpose as double quotes).
For names that consist of alphanumeric characters and underscore, do not start with a digit, and are not reserved words, the square brackets are not needed. They are typically used for columns that have "irregular" names, such as [Column Name] (note the space) or a reserved word like [from].
When SQL Server generates code, it is overly conservative (in my opinion) about the use of square brackets. It uses them for all column names, table names, and even type names in create table statements. Because I never use "irregular" characters in my names, I find all the brackets to be unnecessary clutter.
The dbo is something called a schema. SQL Server uses a three part naming convention for tables in a database: ... The database name defaults to the current data base, if it is not present. The schema defaults to dbo (or another default schema if that has been changed, which is almost never). And, there is a four part naming convention, where the first part is the server name.
I'm writing a script to create a bunch of tables, and I read in the Microsoft documentation that I should use tick marks (aka grave) to enclose database, table, and field names, but when I run it in SQL Server Management Studio, I get a syntax error on the first tick:
CREATE TABLE `active`.`test` ( … )
^syntax error
So I tried running it thru a lint, and it told me that ` is an invalid character, and it suggested removing them, which totally messed up the script.
What gives?
Use square brackets...
CREATE TABLE [active].[test](...)
The documentation you have linked to is:
The SQL query strings for Windows Installer are restricted to the following formats.
This is not the syntax for SQL Server. I suggest looking at the Transact-SQL Reference instead.
You need to use [] instead of the backtick:
CREATE TABLE [active].[test]
Is there a way to tell NHibernate to use square brackets for all table and column names (like [MyColumn]) when generating the SQL schema export for MS SQL Server? I have a legacy database that uses reserved names for certain columns and running the SQL script generated using NH throws an error because of it.
I want to avoid having to specify this separately for each column.
UPDATE: I'm using the correct dialect:
MsSqlConfiguration.MsSql2008.ConnectionString(connectionString)
UPDATE 2: #UpTheCreek pointed me in the right direction - backticks, which helped me find the answer in the "NHibernate in Action" book (p. 76):
There is no way, apart from quoting all table and column names in backticks, to force NHibernate to use quoted identifiers everywhere.
Easier approach:
SchemaMetadataUpdater.QuoteTableAndColumns(config)
(Before building SessionFactory)
That will quote all the reserved names automatically.
Use backticks in your mapping files around the column names. NH should replace these with the correct character for your db dialect (in your case square brackets).
i.e. use:
<class name="SomeClass" table="`SomeTable`">
NB - It won't work with an apostrophe. The backtick is located top left on most keyboards.
You need to use (or write) the correct dialect for your database