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{{Third-party plugin}}
The Query Gramplet takes SQL-like queries and produces a Quick View.
= Examples =
The QueryGramplet in gramps-addons/trunk for gramps/master Gramps 5.0 can now SELECT, UPDATE, and DELETE. Some examples (keywords are showncapitalized, but the SQL parser is case-insensitive; fields that are capitalized are ''macros'' and must be capitalized, see below for more information):
This API is made possible through the generic struct/json interface. It is very little code, because it relies on these generic structures. It should be able to be made solid enough to expose to users (say as a generic filter). The parser can be made more user friendly... it may just throw an error currently.
Here is the grammar for the subset of SQL supported. The SELECT, UPDATE, DELETE, and LIMIT clauses may be in any order. The WHERE clause (if used) must be last.
<pre>
SELECT expr1 [as var1][, expr2 [as var2], ...] FROM table [LIMIT number1[, number2]] [WHERE expression];
... [RAW | NORAW] ...
</pre>
'''table''' is one of:
* col[N] (alias to column)
* aliases
* '''object''' - the primitive gen.lib object (such as Person, Family, etc)
RAW/NORAW: does not turn the results into strings, but leaves the selected values as raw Python. The default is NORAW. Once set, the new setting will remain the default for this session.
FLAT/EXPAND: if FLAT, then the rows are not cross-product JOINED with other multi-valued columns, but rather left as LISTS. Default is EXPAND. Once set, the new setting will remain the default for this session.
The following shortcuts (also called "macros") can be used in expressions and as a field:
A ''macro'' is a low-level text replacement system. We could add other macros, and even allow users to define their own.
== Pre-Defined Functions and Libraries ==
The following are defined for use in your queries:
* Tag(name) - Create or lookup a tag by its name
* re - The Python regular expression library
* random - The Python random library
* db - the current Gramps database
* sdb - Simple Database API to the database
* Today() - a Gramps Date object set to today's date
* Date() - creates a Gramps Date object
* lib - to access gramps.gen.lib object definitions
* _(text) - for translations
Examples:
<pre>
SELECT gramps_id, primary_name.surname_list.surname
FROM person
WHERE any([re.match("Sm.*th", name) for name in col[1]]);
</pre>
Searches all primary_name surnames to find names that start with "Sm" and end in "th". col[1] is primary_name.surname_list.surname, which is a list of surnames.
UPDATE person SET tag_list=Tag("Smith") WHERE SURNAME == "Smith";
== Lists ==
When a attribute is a list, you can select elements from items in the list, and also filter the list. For example, consider a person's parent_family_list. You can select only a single component, say private, of the parent family like:
SELECT parent_family_list("private") FROM person;
This would select only the private component from the parent families.
Likewise, you can filter the list to, say, only show those families that are private:
SELECT parent_family_list(private=True) FROM person;
This will only show (in the finally selected people) the parent families that are private.
Finally, you can both limit, and select from a list:
SELECT parent_family_list("gramps_id", private=True) FROM person;
That will limit the list to be a list of family gramps_id for private families.
You can delete an entire list by assigning None to it:
UPDATE note_list=None from person;
You can delete an item in a list by assigning None to it:
UPDATE note_list[0]=None from person;
= Notes =
4) The SELECT fields use the bracketed notation for list references. Use "event_ref_list[0]".
5) JOINS are not necessary, because it automatically looks up all relations through the handles. In a SELECT, columns with multiple values in a list will appear as an outer-join with other values in the row.
6) UPDATE will work on any field, through a joined object or on the primary object. For example, you can update the birth date of an
10) .handle or .ref automatically look up their references.
11) Shortcut: you can use col[N] in the WHERE clause to reference a column selected. N is zero-based.
SELECT gramps_id, private FROM person WHERE not col[1];
SELECT gramps_id, primary_name.surname_list[1] FROM person WHERE col[1];
13) In a SELECT (for speed reasons), you You do not need to reference a field before you can use it. That is not necessary in the UPDATE or DELETE statements. (The idea here is that SELECTS are done quite frequently, but UPDATES are done rarely, and it doesn't matter if those take a little longer). Maybe we can relax this constraintWHERE clause.
14) The semicolon is optional.
15) Be careful selecting all fields from all records... that could take up a lot of memory, and bring down grampsGramps.
16) This should be fairly fast, but it does call eval(). This might make things a little slower, but made the code much easier to write. And it does use the full power of python.
17) You can use parens parentheses in an "UPDATE table SET field=value" value. Something like:
UPDATE table SET field=(field + 1);
20) If a selected field does not exist in a record, then it will have a value of None. For example, if you are selecting those people that have a second surname on their primary name, and there are some people who do not have a second surname, it will appear as None. If all columns are None, then the item will not be selected at all.
21) If you know that only one value will match, then a "LIMIT 1" may be a way to speed up the query.
= Older documentation for the QueryGramplet in Gramps 3.4 =
[[Image:QuerySmith.png|thumb|left|400px]]
{{-}}
<pre> $ select given_name, surname from people;
$ select * from families;
</pre>
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