26 April 2001 Unicode and Collation Support in MS SQL Server, IUC 18 (Hong Kong) Unicode and Collation Support in Microsoft SQL Server Michael S. Kaplan Software Design Engineer Trigeminal Software, Inc.

26 April 2001 Unicode and Collation Support in MS SQL Server, IUC 18 (Hong Kong) Unicode Support Uses the "N" or national data types from the SQL-92 specification NCHAR, NVARCHAR, NTEXT What the SQL-99 spec says about Unicode Interoperability with other clients

26 April 2001 Unicode and Collation Support in MS SQL Server, IUC 18 (Hong Kong) Collation in SQL Server <= 6.5 No Unicode support at all One code page per server One collation per server No good solution for multilingual support

26 April 2001 Unicode and Collation Support in MS SQL Server, IUC 18 (Hong Kong) Collation in SQL Server 7.0 Unicode datatypes supported Two collations – Unicode – Non-Unicode Number of collations distilled down to the minimum necessary Collation independent of operating system

26 April 2001 Unicode and Collation Support in MS SQL Server, IUC 18 (Hong Kong) Collation in SQL Server 2000 Combined code pages and collations into a single entity

26 April 2001 Unicode and Collation Support in MS SQL Server, IUC 18 (Hong Kong) "Windows" collations 43 language collations – Added for unique code pages – Added for unique ordering Suffix meanings – _BIN (Binary) – _CI/_CS (Case sensitivity) – _AI/_AS (Accent sensitivity) – _KS - kanatype sensitivity (hiragana/katakana) – _WS - width sensitivity (full/half width)

26 April 2001 Unicode and Collation Support in MS SQL Server, IUC 18 (Hong Kong) SQL Collations Provided for backwards compatibility with prior versions of SQL Server

26 April 2001 Unicode and Collation Support in MS SQL Server, IUC 18 (Hong Kong) Collation at four levels Server Database Column Expression

26 April 2001 Unicode and Collation Support in MS SQL Server, IUC 18 (Hong Kong) At the server level Acts as a default for all databases Can be changed with RebuildM.exe in the tools\BINN dir Querying the server collation: SELECT CONVERT(char, SERVERPROPERTY('collation'))

26 April 2001 Unicode and Collation Support in MS SQL Server, IUC 18 (Hong Kong) At the database level Every database has a collation (default is the server collation) Collation can be changed under some circumstances

26 April 2001 Unicode and Collation Support in MS SQL Server, IUC 18 (Hong Kong) At the column level Overrides database level collation Specifies code page for non-Unicode columns Again, can be changed under some circumstances No multilingual columns with separate collations

26 April 2001 Unicode and Collation Support in MS SQL Server, IUC 18 (Hong Kong) At the expression level Can be used to override any other collation uses the COLLATE keyword

26 April 2001 Unicode and Collation Support in MS SQL Server, IUC 18 (Hong Kong) More on the COLLATE keyword COLLATE [ |<SQL_Collation_Name] Specific rules of precedence: – Explicit (two explicits == runtime error) – Implicit (two implicits == no collation) – Default –

26 April 2001 Unicode and Collation Support in MS SQL Server, IUC 18 (Hong Kong) Limitations Features people will want for future versions – LCID --> Collation – ISO string Collation – Creating custom collations?

26 April 2001 Unicode and Collation Support in MS SQL Server, IUC 18 (Hong Kong) Questions?

26 April 2001 Unicode and Collation Support in MS SQL Server, IUC 18 (Hong Kong) Unicode and Collation Support in Microsoft SQL Server