Crate sql_support

A crate with various sql/sqlcipher helpers.

Modules

debug_tools

open_database

Structs

LazyDb

Lazily-loaded database with interruption support

RepeatDisplay

Helper type for printing repeated strings more efficiently. You should use repeat_display or one of the repeat_sql_* helpers to construct it.

UncheckedTransaction

rusqlite, in an attempt to save us from ourselves, needs a mutable ref to a connection to start a transaction. That is a bit of a PITA in some cases, so we offer this as an alternative - but the responsibility of ensuring there are no concurrent transactions is on our head.

Enums

MaybeCached

MaybeCached is a type that can be used to help abstract over cached and uncached rusqlite statements in a transparent manner.

Traits

ConnExt

This trait exists so that we can use these helpers on rusqlite::{Transaction, Connection}. Note that you must import ConnExt in order to call these methods on anything.

Functions

default_max_variable_number

Returns SQLITE_LIMIT_VARIABLE_NUMBER as read from an in-memory connection and cached. connection and cached. That means this will return the wrong value if it’s set to a lower value for a connection using this will return the wrong thing, but doing so is rare enough that we explicitly don’t support it (why would you want to lower this at runtime?).

each_chunk

Helper for the case where you have a &[impl ToSql] of arbitrary length, but need one of no more than the connection’s MAX_VARIABLE_NUMBER (rather, default_max_variable_number()). This is useful when performing batched updates.

each_chunk_mapped

A version of each_chunk for the case when the conversion to to_sql requires an custom intermediate step. For example, you might want to grab a property off of an array of records

each_sized_chunk

each_sized_chunk_mapped

Utility to help perform batched updates, inserts, queries, etc. This is the low-level version of this utility which is wrapped by each_chunk and each_chunk_mapped, and it allows you to provide both the mapping function, and the chunk size.

escape_string_for_pragma

In PRAGMA foo=‘bar’, 'bar' must be a constant string (it cannot be a bound parameter), so we need to escape manually. According to https://www.sqlite.org/faq.html, the only character that must be escaped is the single quote, which is escaped by placing two single quotes in a row.

repeat_display

Construct a RepeatDisplay that will repeatedly call fmt_one with a formatter count times, separated by sep.

repeat_multi_values

Returns a value that formats as num_values instances of (?,?,?,...) (where there are vars_per_value question marks separated by commas in between the ?s).

repeat_sql_values

Returns a value that formats as count instances of (?) separated by commas.

repeat_sql_vars

Returns a value that formats as count instances of ? separated by commas.

run_maintenance

Run maintenance on the DB

setup_sqlite_defaults

Default SQLite pragmas