我想创建一个以下类型的字典,
var data = new Dictionary<string, Dictionary<string, Dictionary<string, int>>>();
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当我尝试以下列方式向字典添加值时,我得到一个KeyNotFound异常.
data[key1][key2][key3]= 3;
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我在这做错了什么?我假设如果在字典中找不到密钥,它会自动添加到字典中.
否则有没有办法在运行时添加键?
我期待以下类型的输出:
[male,[animal,[legs,4]
[eyes,2]]
[human,[hands,2]
[ears,2]]
[female,[animal,[nose,1]
[eyes,2]]
[bird,[wings,2]
[legs,2]]
Run Code Online (Sandbox Code Playgroud) 我有以下用于创建表的查询,
CREATE TABLE IF NOT EXISTS company (
id uuid CONSTRAINT companyid PRIMARY KEY DEFAULT gen_random_uuid(),
name varchar(128) NOT NULL,
db_uri varchar(255) NOT NULL,
c_uri varchar(255) NOT NULL,
date_c timestamp DEFAULT now(),
date_m timestamp DEFAULT now()
) WITH (fillfactor=90);
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当我通过 pgAdminIII 运行它时,出现以下错误。
ERROR: function gen_random_uuid() does not exist
HINT: No function matches the given name and argument types. You might need to add explicit type casts.
********** Error **********
ERROR: function gen_random_uuid() does not exist
SQL state: 42883
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