* removes the lifetime from Row
* removes MySqlQueryAs, SqliteQueryAs, etc. (no longer needed)
* introduce query_scalar
* introduce Decode::accepts to allow overriding runtime type checking
per-type (replaces TypeInfo::compatible)
* introduce Encode::produces to allow overriding the encoded type per-value
* adds a lifetime to Arguments (and introduce the HRTB HasArguments)
to support zero-copy encoding with SQLite
* renames Database::RawBuffer to HasArguments::ArgumentBuffer
* introduce Connect::connect_with to provide an ConnectOptions type
explicitly to opt-out of connection string parsing
* introduce Value and ValueRef traits to allow decoding-deferred
extraction of values from Rows
* introduce Encode::encode_by_ref and change Encode::encode to take
by-value to try and re-use memory where possible
* use thiserror to generate sqlx::Error
* [!] temporarily removes query logging
* [!] temporarily removes transactions
Before, the query would be formatted equivalent to the input string:
```
[2020-04-18T23:47:32Z DEBUG sqlx_core::postgres::executor] SELECT id, queue, ..., elapsed: 2.320µs
SELECT id, queue, payload, status, priority, created_at, updated_at
FROM jobs
WHERE status = $1
ORDER BY priority ASC, created_at ASC
```
After, the query is formatted cleanly and consistently:
```
[2020-04-19T00:30:18Z DEBUG sqlx_core::postgres::executor] SELECT id, queue, ..., elapsed: 2.280µs
SELECT
id,
queue,
payload,
status,
priority,
created_at,
updated_at
FROM
jobs
WHERE
status = $1
ORDER BY
priority ASC,
created_at ASC
```
This uses the `sqlformat` crate, which was ported from the
Javascript `sql-formatter-plus` library specifically for this purpose.
* implement for &serde_json::RawValue
* sqlx::types::Json<T> is a common type that all JSON-compatible databases can implement for,
postgres implements Json<T> as JSONB
* sqlx::postgres::types::PgJson<T> resolves to JSON
* sqlx::postgres::types::PgJsonB<T> resolves to JSONB
This introduces two new wrapper types `Json` and `Jsonb`, currently
exported by `sqlx::postgres::{Json, Jsonb}` and adds serde and
serde_json as optional dependencies, under the feature flag `json`.
Wrapping types in `Json[b]` that implement `serde::Deserialize` and
`serde::Serialize` allows them to be decoded and encoded respectivly.
This changeset introduces an interface for using PostgreSQL's LISTEN
functionality from within sqlx.
The listen interface is implemented over the PgConnection, PgPool & the
PgPoolConnection types for ease of use. In the case of PgPool, a new
connection is acquired, and is then used for LISTEN functionality.
Closes#87
