Convert VARCHAR() columns to NVARCHAR()
- by ChrisD
We recently underwent an upgrade that required us to change our database columns from varchar to NVarchar, to support unicode characters. Digging through the internet, I found a base script which I modified to handle reserved word table names, and maintain the NULL/NotNull constraint of the columns. I Ran this script use NWOperationalContent – Your Catalog Name here GO SELECT 'ALTER TABLE ' + isnull(schema_name(syo.id), 'dbo') + '.[' + syo.name +'] ' + ' ALTER COLUMN [' + syc.name + '] NVARCHAR(' + case syc.length when -1 then 'MAX' ELSE convert(nvarchar(10),syc.length) end + ') '+ case syc.isnullable when 1 then ' NULL' ELSE ' NOT NULL' END +';' FROM sysobjects syo JOIN syscolumns syc ON syc.id = syo.id JOIN systypes syt ON syt.xtype = syc.xtype WHERE syt.name = 'varchar' and syo.xtype='U' which produced a series of ALTER statements which I could then execute the tables. In some cases I had to drop indexes, alter the tables, and re-create the indexes. There might have been a better way to do that, but manually dropping them got the job done. use NWMerchandisingContent GO ALTER TABLE Locale Drop Constraint PK_Locale ALTER TABLE Country DROP CONSTRAINT PK_Country GO ALTER TABLE dbo.[Campaign] ALTER COLUMN [ActorKey] NVARCHAR(200) NOT NULL; ALTER TABLE dbo.[BundleLocalization] ALTER COLUMN [Locale] NVARCHAR(8) NOT NULL; ALTER TABLE dbo.[BundleLocalization] ALTER COLUMN [UnitOfmeasure] NVARCHAR(200) NULL; ALTER TABLE dbo.[BundleLocalization] ALTER COLUMN [ActorKey] NVARCHAR(200) NOT NULL; ALTER TABLE dbo.[BundleComponentLocalization] ALTER COLUMN [Locale] NVARCHAR(8) NOT NULL; ALTER TABLE dbo.[BundleComponentLocalization] ALTER COLUMN [Imperative] NVARCHAR(MAX) NULL; ALTER TABLE dbo.[BundleComponentLocalization] ALTER COLUMN [Instructions] NVARCHAR(MAX) NULL; ALTER TABLE dbo.[BundleComponentLocalization] ALTER COLUMN [ActorKey] NVARCHAR(200) NOT NULL; ALTER TABLE dbo.[BundleComponent] ALTER COLUMN [ActorKey] NVARCHAR(200) NOT NULL; ALTER TABLE dbo.[Bundle] ALTER COLUMN [ActorKey] NVARCHAR(200) NOT NULL; ALTER TABLE dbo.[Banner] ALTER COLUMN [ActorKey] NVARCHAR(200) NOT NULL; ALTER TABLE dbo.[Video] ALTER COLUMN [Link] NVARCHAR(512) NOT NULL; ALTER TABLE dbo.[Video] ALTER COLUMN [ActorKey] NVARCHAR(200) NOT NULL; ALTER TABLE dbo.[ProductUsage] ALTER COLUMN [VideoLink] NVARCHAR(512) NOT NULL; ALTER TABLE dbo.[ProductUsage] ALTER COLUMN [ActorKey] NVARCHAR(200) NOT NULL; ALTER TABLE dbo.[Thumbnail] ALTER COLUMN [ActorKey] NVARCHAR(200) NOT NULL; ALTER TABLE dbo.[SkuLocalization] ALTER COLUMN [Locale] NVARCHAR(8) NOT NULL; ALTER TABLE dbo.[SkuLocalization] ALTER COLUMN [UnitOfMeasure] NVARCHAR(150) NOT NULL; ALTER TABLE dbo.[SkuLocalization] ALTER COLUMN [SwatchColor] NVARCHAR(50) NOT NULL; etc.. GO ALTER TABLE Locale ADD CONSTRAINT PK_Locale PRIMARY KEY (LocaleId) ALTER TABLE Country ADD CONSTRAINT PK_Country PRIMARY KEY (CountryId) Note that this alter is non-destructive to the data. Hope this helps.
