[英]How to add a boolean datatype column to an existing table in sql?
I have a table called person in my database.我的数据库中有一个名为person的表。 I want to add another column to the same table and it's a Boolean datatype column .
我想在同一个表中添加另一列,它是一个 Boolean 数据类型的列。 I have tried following queries but it says syntax error near default.
我试过以下查询,但它说接近默认的语法错误。 I know this is a common and there are lot of answers.
我知道这很常见,并且有很多答案。 I have tried many of them and couldn't figure out to make it work.
我已经尝试了很多,但无法弄清楚如何让它发挥作用。 So please help me.
所以请帮助我。
queries I have tried我试过的查询
ALTER TABLE person add column "AdminApproved" BOOLEAN SET default FALSE;
ALTER TABLE person alter column "AdminApproved" BOOLEAN SET default FALSE;
I have tried without SET key word too.我也尝试过不使用SET关键字。
In SQL SERVER it is BIT
, though it allows NULL
to be stored在 SQL SERVER 中它是
BIT
,尽管它允许存储NULL
ALTER TABLE person add [AdminApproved] BIT default 'FALSE';
Also there are other mistakes in your query您的查询中还有其他错误
When you alter a table to add column no need to mention column
keyword in alter
statement当您更改表以添加列时,无需在
alter
语句中提及column
关键字
For adding default constraint no need to use SET
keyword添加默认约束不需要使用
SET
关键字
Default value for a BIT
column can be ('TRUE' or '1')
/ ('FALSE' or 0)
. BIT
列的默认值可以是('TRUE' or '1')
/ ('FALSE' or 0)
。 TRUE
or FALSE
needs to mentioned as string
not as Identifier TRUE
或FALSE
需要作为string
而不是作为标识符提及
The answer given by Pரதீப் creates a nullable bool, not a bool, which may be fine for you. Pரதீப்给出的答案创建了一个可为空的布尔值,而不是一个布尔值,这对您来说可能没问题。 For example in C# it would create:
bool? AdminApproved
例如在 C# 中它会创建:
bool? AdminApproved
bool? AdminApproved
not bool AdminApproved
. bool? AdminApproved
不是bool AdminApproved
。
If you need to create a bool (defaulting to false):如果您需要创建一个 bool(默认为 false):
ALTER TABLE person
ADD AdminApproved BIT
DEFAULT 0 NOT NULL;
In phpmyadmin, If you need to add a boolean datatype column to an existing table with default value true:在 phpmyadmin 中,如果您需要将布尔数据类型列添加到默认值为 true 的现有表中:
ALTER TABLE books
isAvailable boolean default true;
下面的查询对我有用,默认值为 false;
ALTER TABLE cti_contract_account ADD ready_to_audit BIT DEFAULT 0 NOT NULL;
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