英文:
sqlite append column to existing table
问题
我有一个名为"MyTable"的表，其中有3列，分别命名为"A"，"B"和"C"。
现在，我使用SELECT和LENGTH函数，类似于SELECT LENGTH("A") FROM MyTable。
因此，我只是获得了另一列，其中包含了从"A"列的每一行中获取的字符长度。
然而，我不知道如何将这一列附加到MyTable。
换句话说，如果我的问题重新表述一下，我想知道如何创建另一列，其中包含特定列的字符长度。
我尝试创建一个新表，其中包括从SELECT LENGTH("A") FROM创建的列，以及CREATE新表 AS SELECT LENGTH("A") FROM。但是，它显示语法错误。
英文:
I have a table(MyTable) with 3 columns named as "A","B",and "C".
Now, I use SELECT and LENGTH function like SELECT LENGTH("A") FROM MyTable.
So, I just got another column with rows of characters length from each row of column A.
However, I have no clue to append this to MyTable.
In other words, if my question is rephrased, I wonder how to make another column with characters length of a certain column.
I tried to make new table with the column made from SELECT LENGTH("A") FROM, and CREATE new table AS SELECT LENGTH("A") FROM. But, it shows syntax error.
答案1
得分: 1
我猜你得到的错误是因为你没有为新列指定名称。你可以尝试这样做：
CREATE TABLE NewTable AS SELECT A, B, C, LENGTH(A) AS A_length FROM MyTable;
正如 @forpas 所说，你的语法错误是由一个拼写错误引起的，使用了 LENTH 而不是 LENGTH。
英文:
I guess the error you are getting is because you are not specifying name for the new column. Can you try this:
CREATE TABLE NewTable AS SELECT A, B, C, LENGTH(A) AS A_length FROM MyTable;
As @forpas said, your syntax error was caused by a typo - using LENTH instead of LENGTH.
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