@@IDENTITY returns the last identity value generated for any table in the current session, across all scopes. You need to be careful here, since it’s across scopes. You could get a value from a trigger, instead of your current statement. SCOPE_IDENTITY() returns the last identity value generated for any table in the current session and … Read more
There are a few steps to see the tables in an SQLite database: List the tables in your database: .tables List how the table looks: .schema tablename Print the entire table: SELECT * FROM tablename; List all of the available SQLite prompt commands: .help
Group By X means put all those with the same value for X in the one group. Group By X, Y means put all those with the same values for both X and Y in the one group. To illustrate using an example, let’s say we have the following table, to do with who is … Read more
Syntax strictly depends on which SQL DBMS you’re using. Here are some ways to do it in ANSI/ISO (aka should work on any SQL DBMS), MySQL, SQL Server, and Oracle. Be advised that my suggested ANSI/ISO method will typically be much slower than the other two methods, but if you’re using a SQL DBMS other … Read more
My favorite answer is as what the first sentence in this thread suggested. Use an Adjacency List to maintain the hierarchy and use Nested Sets to query the hierarchy. The problem up until now has been that the coversion method from an Adjacecy List to Nested Sets has been frightfully slow because most people use … Read more
Search Tables: SELECT c.name AS ‘ColumnName’ ,t.name AS ‘TableName’ FROM sys.columns c JOIN sys.tables t ON c.object_id = t.object_id WHERE c.name LIKE ‘%MyName%’ ORDER BY TableName ,ColumnName; Search Tables and Views: SELECT COLUMN_NAME AS ‘ColumnName’ ,TABLE_NAME AS ‘TableName’ FROM INFORMATION_SCHEMA.COLUMNS WHERE COLUMN_NAME LIKE ‘%MyName%’ ORDER BY TableName ,ColumnName;
UNION removes duplicate records (where all columns in the results are the same), UNION ALL does not. There is a performance hit when using UNION instead of UNION ALL, since the database server must do additional work to remove the duplicate rows, but usually you do not want the duplicates (especially when developing reports). To … Read more
You need to specify what table you are deleting from. Here is a version with an alias: DELETE w FROM WorkRecord2 w INNER JOIN Employee e ON EmployeeRun=EmployeeNo WHERE Company = ‘1’ AND Date=”2013-05-06″
Try: INSERT INTO table1 ( column1 ) SELECT col1 FROM table2 This is standard ANSI SQL and should work on any DBMS It definitely works for: Oracle MS SQL Server MySQL Postgres SQLite v3 Teradata DB2 Sybase Vertica HSQLDB H2 AWS RedShift SAP HANA Google Spanner
I had same question, and after reading all answers here I definitely stay with SINGULAR, reasons: Reason 1 (Concept). You can think of bag containing apples like “AppleBag”, it doesn’t matter if contains 0, 1 or a million apples, it is always the same bag. Tables are just that, containers, the table name must describe … Read more