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--- 1. Solutions to common issues
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--- Resolving the "Divide by zero" error (by example)
-DECLARE @denominator INT
-SET @denominator = 0
---SELECT 1 / 0
-SELECT 1 / ISNULL(NULLIF(@denominator, 0), 1)
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---Handling the error “The conversion of a char data type to a datetime data 
---type resulted in an out-of-range datetime value”
---Change the default language to “us_english” for the given SQL Server login:
-USE [master];
-ALTER LOGIN "LOGIN_NAME" WITH DEFAULT_LANGUAGE = us_english;
---Best practice: Always use the ISO date format in your data applications/T-SQL scripts: YYYY-MM-DD
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---Handling the error “Database [Database_Name] cannot be upgraded because it is read-only 
---or has read-only files”
---Make sure that the user account on which the SQL Server instance database engine is 
---running has full access to the database files.
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--- 2. Basic String Functions
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--- Returns @length characters from @expression starting from @start_index
-SELECT SUBSTRING(@expression, @start_index, @length)
-SELECT SUBSTRING('This is a Test', 1, 4)
--- Finds the given @pattern in the @string and replaces it with the @replacement_string
-SELECT REPLACE(@string, @pattern, @replacement_string)
-SELECT REPLACE('This is a Test', 'Test', 'New Test')
--- Returns the size of @string in terms of number of characters
-SELECT LEN(@string)
-SELECT LEN('This is a Test')
--- Returns the first @num_chars characters of the @string counting from the left
-SELECT LEFT(@string, @num_chars)
-SELECT LEFT('This is a Test',4)
--- Returns the first @num_chars characters of the @string counting from the right
-SELECT RIGHT(@string, @num_chars)
-SELECT RIGHT('This is a Test',4)
--- Removes the leading blank spaces
-SELECT LTRIM(@expression)
-SELECT LTRIM(' This is a Test')
--- Removes the trailing blank spaces
-SELECT RTRIM(@expression)
-SELECT RTRIM('This is a Test ')
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--- 3. Performance-Related Tips
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--- Avoiding locking when reading data (however, dirty reads are allowed)
--- You need to take into consideration, possible dirty-read issues when using this approach
-SELECT [columnName]
-FROM [tableName] WITH (NOLOCK)
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--- Rebuild a specific index with using parameters
-USE [DATABASE_NAME];
-ALTER INDEX [INDEX_NAME] ON [SCHEMA.TABLE]
-REBUILD WITH (FILLFACTOR=[FILL_FACTOR_VALUE_BETWEEN_0_100], ONLINE=[ON|OFF]);
--- Rebuild all indexes in a table with using parameters
-USE [DATABASE_NAME];
-ALTER INDEX ALL ON [SCHEMA.TABLE]
-REBUILD WITH (FILLFACTOR=[FILL_FACTOR_VALUE_BETWEEN_0_100], ONLINE=[ON|OFF]);
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--- Updating database tables without causing blocking
--- You need to take into consideration, possible dirty-read issues when using this approach
-UPDATE [TABLE_NAME] WITH (READPAST)
-SET …
-WHERE …
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--- 4. Maintenance-Related Tips
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--- Truncating a data/log file
-USE [DBName];
-DBCC SHRINKFILE ([Data_Log_LogicalName],TRUNCATEONLY);
--- Renaming a Windows login
-ALTER LOGIN "[Domain or Server Name]\[Windows Username]"
-WITH NAME="[New Domain or New Server Name]\[Windows Username]";
--- Renaming a SQL Server login
-ALTER LOGIN "[SQL Server Login Name]"
-WITH NAME="[New SQL Server Login Name]";
--- Creating Logins for orphaned SQL Server users
-USE [DBName];
-EXEC sp_change_users_login 'Auto_Fix', '[UserName]', NULL, '[Password]';
--- Changing the Database Owner in a SQL Server Database (SQL Login)
-USE [DBName];
-EXEC sp_changedbowner '[SQL_Login_Name]';
--- Changing the Database Owner in a SQL Server Database (Windows Login)
-USE [DBName];
-EXEC sp_changedbowner '[DomainNameUserName]'