{"id":27630,"date":"2024-03-16T08:51:52","date_gmt":"2024-03-16T08:51:52","guid":{"rendered":"https:\/\/www.silicloud.com\/blog\/how-to-write-a-primary-key-constraint-in-sql-server\/"},"modified":"2024-03-22T11:30:06","modified_gmt":"2024-03-22T11:30:06","slug":"how-to-write-a-primary-key-constraint-in-sql-server","status":"publish","type":"post","link":"https:\/\/www.silicloud.com\/blog\/how-to-write-a-primary-key-constraint-in-sql-server\/","title":{"rendered":"How to write a primary key constraint in SQL Server?"},"content":{"rendered":"

In SQL Server, the following syntax can be used to create a primary key constraint:<\/p>\n

ALTER TABLE table_name\r\nADD CONSTRAINT constraint_name PRIMARY KEY (column1, column2, ...)<\/pre>\n
In this example, `table_name` is the name of the table where the primary key constraint is being added, `constraint_name` is the name of the primary key constraint (optional), and `column1, column2, …` are the columns to be used as the primary key. For instance, to create a primary key constraint named `PK_Users` with the `ID` column as the primary key:<\/p>\n
ALTER TABLE Users\r\nADD CONSTRAINT PK_Users PRIMARY KEY (ID)<\/pre>\n
One option to directly define a primary key constraint when creating a table is by using the following syntax:<\/p>\n
CREATE TABLE table_name\r\n(\r\n
    column1 datatype PRIMARY KEY,<\/p>\r\n
    column2 datatype,<\/p>\r\n
    \u2026\r\n)<\/p><\/pre>\n
For example, create a table called Users with the ID column as the primary key.<\/p>\n
CREATE TABLE Users\r\n(
<\/p>\r\n
    ID int PRIMARY KEY,<\/p>\r\n
    Name varchar(50),<\/p>\r\n
    \u2026\r\n)<\/p><\/pre>\n
Please note that the purpose of a primary key constraint is to ensure that a column or group of columns in a table is unique and not empty. Therefore, the values in the primary key column cannot be duplicated and cannot be NULL.<\/p>\n","protected":false},"excerpt":{"rendered":"
In SQL Server, the following syntax can be used to create a primary key constraint: ALTER TABLE table_name ADD CONSTRAINT constraint_name PRIMARY KEY (column1, column2, …) In this example, `table_name` is the name of the table where the primary key constraint is being added, `constraint_name` is the name of the primary key constraint (optional), and `column1, column2, …` are the columns to be used […]<\/p>\n","protected":false},"author":14,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_import_markdown_pro_load_document_selector":0,"_import_markdown_pro_submit_text_textarea":"","footnotes":""},"categories":[1],"tags":[],"class_list":["post-27630","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"yoast_head":"\nHow to write a primary key constraint in SQL Server? - Blog - Silicon Cloud<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.silicloud.com\/blog\/how-to-write-a-primary-key-constraint-in-sql-server\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"How to write a primary key constraint in SQL Server?\" \/>\n<meta property=\"og:description\" content=\"In SQL Server, the following syntax can be used to create a primary key constraint: ALTER TABLE table_name ADD CONSTRAINT constraint_name PRIMARY KEY (column1, column2, ...) In this example, `table_name` is the name of the table where the primary key constraint is being added, `constraint_name` is the name of the primary key constraint (optional), and `column1, column2, …` are the columns to be used […]\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.silicloud.com\/blog\/how-to-write-a-primary-key-constraint-in-sql-server\/\" \/>\n<meta property=\"og:site_name\" content=\"Blog - Silicon Cloud\" \/>\n<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/SiliCloudGlobal\/\" \/>\n<meta property=\"article:published_time\" content=\"2024-03-16T08:51:52+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2024-03-22T11:30:06+00:00\" \/>\n<meta name=\"author\" content=\"Noah Thompson\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:creator\" content=\"@SiliCloudGlobal\" \/>\n<meta name=\"twitter:site\" content=\"@SiliCloudGlobal\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"Noah Thompson\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"1 minute\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\/\/www.silicloud.com\/blog\/how-to-write-a-primary-key-constraint-in-sql-server\/#article\",\"isPartOf\":{\"@id\":\"https:\/\/www.silicloud.com\/blog\/how-to-write-a-primary-key-constraint-in-sql-server\/\"},\"author\":{\"name\":\"Noah Thompson\",\"@id\":\"https:\/\/www.silicloud.com\/blog\/#\/schema\/person\/2e83cc6ab9f60d36921c2d0f9f280f4a\"},\"headline\":\"How to write a primary key constraint in SQL Server?\",\"datePublished\":\"2024-03-16T08:51:52+00:00\",\"dateModified\":\"2024-03-22T11:30:06+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\/\/www.silicloud.com\/blog\/how-to-write-a-primary-key-constraint-in-sql-server\/\"},\"wordCount\":164,\"commentCount\":0,\"publisher\":{\"@id\":\"https:\/\/www.silicloud.com\/blog\/#organization\"},\"inLanguage\":\"en-US\"},{\"@type\":\"WebPage\",\"@id\":\"https:\/\/www.silicloud.com\/blog\/how-to-write-a-primary-key-constraint-in-sql-server\/\",\"url\":\"https:\/\/www.silicloud.com\/blog\/how-to-write-a-primary-key-constraint-in-sql-server\/\",\"name\":\"How to write a primary key constraint in SQL Server? 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