Column settings allow for options to be set for individual columns of data from the database.
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Physical Name
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The name of the column used by the database.
Label
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The display name to be used in Jira.
Type
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The data type , (such as number, string, date, etc.- what ) is this used for ? - data validations on INSERT and (, more importantly) - indexing, so you can index a text column as string, , indexing. A text column can be indexed as a string and a number column as number , so you can use the correct operators when searching with JQL.
Default Value
The value that should be selected before the user inputs a new value.
PK
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The column is the primary key in the connected database.
Searchable
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The column data should be searchable. This setting makes the column appear or not appear in the search window. The search script should also be updated in order to make sure the results for this column are being returned.
Required
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The column should be required and must be filled in prior to the user updating the values.
Constraints
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Settings that require the input data to match certain conditions prior to the user saving the values. See Constrains for more information about using constraints.