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* Automatically set PRAGMAs using connection query params Introduce the flexibility to adjust certain PRAGMAs of the SQLite3 connection without having to hardcode those in your codebase (and wait for compilation). This allows applications to use `DATABASE_URL` to dynamically fine tune their SQLite3 configuration. The change complements `#setup_connection` that offers, via code, the option to perform queries on setup of each connection. Only a few PRAGMAs necessary to allow more performant concurrent reads and reduce write locking. These pragmas are detected and combined in a single SQL string to reduce to 1 the number of calls to `sqlite3_exec` C function. There is no validation of supplied values as SQLite3 automatically ignores incorrect values for these pragmas. Closes #84 References: - https://www.sqlite.org/pragma.html * Simplify PRAGMA mapping and detection No longer prefix PRAGMAS with `_`, so the mapping between the real SQLite3 pragmas and the usage in the URI is more direct. Use macros instead of case to detect pragmas from URI params and return those as NamedTuple. * Update README.md --------- Co-authored-by: Brian J. Cardiff <bcardiff@gmail.com>
2.8 KiB
2.8 KiB
crystal-sqlite3 ![Build Status](https://travis-ci.org/crystal-lang/crystal-sqlite3.svg?branch=master)
SQLite3 bindings for Crystal.
Check crystal-db for general db driver documentation. crystal-sqlite3 driver is registered under sqlite3://
uri.
Installation
Add this to your application's shard.yml
:
dependencies:
sqlite3:
github: crystal-lang/crystal-sqlite3
Usage
require "sqlite3"
DB.open "sqlite3://./data.db" do |db|
db.exec "create table contacts (name text, age integer)"
db.exec "insert into contacts values (?, ?)", "John Doe", 30
args = [] of DB::Any
args << "Sarah"
args << 33
db.exec "insert into contacts values (?, ?)", args: args
puts "max age:"
puts db.scalar "select max(age) from contacts" # => 33
puts "contacts:"
db.query "select name, age from contacts order by age desc" do |rs|
puts "#{rs.column_name(0)} (#{rs.column_name(1)})"
# => name (age)
rs.each do
puts "#{rs.read(String)} (#{rs.read(Int32)})"
# => Sarah (33)
# => John Doe (30)
end
end
end
DB::Any
Time
is implemented asTEXT
column usingSQLite3::DATE_FORMAT_SUBSECOND
format (orSQLite3::DATE_FORMAT_SECOND
if the text does not contain a dot).Bool
is implemented asINT
column mapping0
/1
values.
Setting PRAGMAs
You can adjust certain SQLite3 PRAGMAs automatically when the connection is created by using the query parameters:
require "sqlite3"
DB.open "sqlite3://./data.db?journal_mode=wal&synchronous=normal" do |db|
# this database now uses WAL journal and normal synchronous mode
# (defaults were `delete` and `full`, respectively)
end
The following is the list of supported options:
Name | Connection key |
---|---|
Busy Timeout | busy_timeout |
Cache Size | cache_size |
Foreign Keys | foreign_keys |
Journal Mode | journal_mode |
Synchronous | synchronous |
WAL autocheckoint | wal_autocheckpoint |
Please note there values passed using these connection keys are passed directly to SQLite3 without check or evaluation. Using incorrect values result in no error by the library.