use async_trait::async_trait;
use sqlx::{
postgres::{PgPool, PgRow},
Column as SqlxColumn, Row as SqlxRow, TypeInfo, ValueRef,
};
use crate::db::error::DbError;
use crate::db::traits::SqlClient;
use crate::db::types::{Column, ColumnSchema, DbQueryResult, ForeignKey, Row, TableKind, TableObject, Value};
pub struct PostgresConnector {
pool: Option<PgPool>,
}
impl PostgresConnector {
pub fn new() -> Self {
Self { pool: None }
}
fn pool(&self) -> Result<&PgPool, DbError> {
self.pool.as_ref().ok_or(DbError::NotConnected)
}
}
#[async_trait]
impl SqlClient for PostgresConnector {
async fn connect(&mut self, url: &str) -> Result<(), DbError> {
let pool = PgPool::connect(url)
.await
.map_err(|e| DbError::ConnectionFailed(e.to_string()))?;
self.pool = Some(pool);
Ok(())
}
async fn disconnect(&mut self) -> Result<(), DbError> {
if let Some(pool) = self.pool.take() {
pool.close().await;
}
Ok(())
}
async fn execute(&self, query: &str) -> Result<u64, DbError> {
let result = sqlx::query(query)
.execute(self.pool()?)
.await
.map_err(|e| DbError::QueryFailed(e.to_string()))?;
Ok(result.rows_affected())
}
async fn fetch_all(&self, query: &str) -> Result<DbQueryResult, DbError> {
let rows: Vec<PgRow> = sqlx::query(query)
.fetch_all(self.pool()?)
.await
.map_err(|e| DbError::QueryFailed(e.to_string()))?;
if rows.is_empty() {
return Ok(DbQueryResult {
columns: vec![],
rows: vec![],
rows_affected: 0,
});
}
let columns: Vec<Column> = rows[0]
.columns()
.iter()
.map(|c| Column {
name: c.name().to_string(),
type_name: c.type_info().name().to_string(),
})
.collect();
let mapped_rows: Vec<Row> = rows
.iter()
.map(|r| Row {
values: (0..r.len()).map(|i| pg_value(r, i)).collect(),
})
.collect();
let count = mapped_rows.len() as u64;
Ok(DbQueryResult {
columns,
rows: mapped_rows,
rows_affected: count,
})
}
async fn get_tables(&self) -> Result<Vec<String>, DbError> {
let rows: Vec<PgRow> = sqlx::query(
"SELECT table_name FROM information_schema.tables \
WHERE table_schema = 'public' AND table_type = 'BASE TABLE' \
ORDER BY table_name",
)
.fetch_all(self.pool()?)
.await
.map_err(|e| DbError::QueryFailed(e.to_string()))?;
Ok(rows
.iter()
.map(|r| r.try_get::<String, _>(0).unwrap_or_default())
.collect())
}
async fn get_table_objects(&self) -> Result<Vec<TableObject>, DbError> {
let rows: Vec<PgRow> = sqlx::query(
"SELECT table_name, table_type FROM information_schema.tables \
WHERE table_schema = 'public' AND table_type IN ('BASE TABLE', 'VIEW') \
ORDER BY table_name",
)
.fetch_all(self.pool()?)
.await
.map_err(|e| DbError::QueryFailed(e.to_string()))?;
Ok(rows.iter().map(|r| {
let name = r.try_get::<String, _>(0).unwrap_or_default();
let type_str = r.try_get::<String, _>(1).unwrap_or_default();
let kind = if type_str == "VIEW" { TableKind::View } else { TableKind::Table };
TableObject { name, kind }
}).collect())
}
async fn get_schema(&self, table: &str) -> Result<Vec<ColumnSchema>, DbError> {
let pool = self.pool()?;
let safe = table.replace('\'', "").replace('"', "");
let query = format!(
r#"SELECT
a.attname::text AS column_name,
pg_catalog.format_type(a.atttypid, a.atttypmod) AS data_type,
(NOT a.attnotnull) AS is_nullable,
EXISTS(
SELECT 1 FROM pg_constraint c
WHERE c.conrelid = a.attrelid
AND c.contype = 'p'
AND a.attnum = ANY(c.conkey)
) AS is_pk,
(
SELECT rc.relname::text
FROM pg_constraint c
JOIN pg_class rc ON rc.oid = c.confrelid
WHERE c.conrelid = a.attrelid
AND c.contype = 'f'
AND a.attnum = ANY(c.conkey)
LIMIT 1
) AS foreign_table_name,
(
SELECT ra.attname::text
FROM pg_constraint c
JOIN pg_attribute ra ON ra.attrelid = c.confrelid
AND ra.attnum = c.confkey[1]
WHERE c.conrelid = a.attrelid
AND c.contype = 'f'
AND a.attnum = ANY(c.conkey)
LIMIT 1
) AS foreign_column_name
FROM pg_attribute a
JOIN pg_class cl ON cl.oid = a.attrelid
JOIN pg_namespace n ON n.oid = cl.relnamespace
WHERE n.nspname = 'public'
AND cl.relname = '{safe}'
AND a.attnum > 0
AND NOT a.attisdropped
ORDER BY a.attnum"#
);
let rows: Vec<PgRow> = sqlx::query(&query)
.fetch_all(pool)
.await
.map_err(|e| DbError::QueryFailed(e.to_string()))?;
let mut schema = vec![];
for row in &rows {
let name: String = row.try_get("column_name").unwrap_or_default();
let type_name: String = row.try_get("data_type").unwrap_or_default();
let is_nullable: bool = row.try_get("is_nullable").unwrap_or(true);
let is_pk: bool = row.try_get("is_pk").unwrap_or(false);
let fk_table: Option<String> = row.try_get("foreign_table_name").unwrap_or(None);
let fk_col: Option<String> = row.try_get("foreign_column_name").unwrap_or(None);
let fk = match (fk_table, fk_col) {
(Some(t), Some(c)) if !t.is_empty() => Some(ForeignKey { table: t, column: c }),
_ => None,
};
schema.push(ColumnSchema { name, type_name, is_pk, is_nullable, fk });
}
Ok(schema)
}
}
fn pg_value(row: &PgRow, index: usize) -> Value {
use chrono::{DateTime, NaiveDate, NaiveDateTime, NaiveTime, Utc};
let raw = row.try_get_raw(index).unwrap();
if raw.is_null() {
return Value::Null;
}
let tn = raw.type_info().name().to_string();
let marker = || Value::Text(format!("<?{tn}>"));
match tn.as_str() {
"BOOL" => row.try_get::<bool, _>(index).map(Value::Bool).unwrap_or_else(|_| marker()),
"INT2" => row.try_get::<i16, _>(index).map(|v| Value::Int(v as i64)).unwrap_or_else(|_| marker()),
"INT4" => row.try_get::<i32, _>(index).map(|v| Value::Int(v as i64)).unwrap_or_else(|_| marker()),
"INT8" => row.try_get::<i64, _>(index).map(Value::Int).unwrap_or_else(|_| marker()),
"FLOAT4" => row.try_get::<f32, _>(index).map(|v| Value::Float(v as f64)).unwrap_or_else(|_| marker()),
"FLOAT8" => row.try_get::<f64, _>(index).map(Value::Float).unwrap_or_else(|_| marker()),
"NUMERIC" => row.try_get::<bigdecimal::BigDecimal, _>(index)
.map(|d| Value::Text(crate::db::types::format_decimal(d)))
.unwrap_or_else(|_| marker()),
"BYTEA" => row.try_get::<Vec<u8>, _>(index).map(Value::Bytes).unwrap_or_else(|_| marker()),
"DATE" => row.try_get::<NaiveDate, _>(index).map(|d| Value::Text(d.to_string())).unwrap_or_else(|_| marker()),
"TIME" => row.try_get::<NaiveTime, _>(index).map(|t| Value::Text(t.to_string())).unwrap_or_else(|_| marker()),
"TIMESTAMP" => row.try_get::<NaiveDateTime, _>(index).map(|dt| Value::Text(dt.to_string())).unwrap_or_else(|_| marker()),
"TIMESTAMPTZ" => row.try_get::<DateTime<Utc>, _>(index).map(|dt| Value::Text(dt.to_rfc3339())).unwrap_or_else(|_| marker()),
"UUID" => row.try_get::<uuid::Uuid, _>(index).map(|u| Value::Text(u.to_string())).unwrap_or_else(|_| marker()),
"JSON" | "JSONB" => row.try_get::<serde_json::Value, _>(index).map(|v| Value::Text(v.to_string())).unwrap_or_else(|_| marker()),
s if s.starts_with('_') => {
if let Ok(v) = row.try_get::<Vec<String>, _>(index) {
return Value::Text(format!("[{}]", v.join(", ")));
}
if let Ok(v) = row.try_get::<Vec<i64>, _>(index) {
return Value::Text(format!("[{}]", v.iter().map(|n| n.to_string()).collect::<Vec<_>>().join(", ")));
}
if let Ok(v) = row.try_get::<Vec<bool>, _>(index) {
return Value::Text(format!("[{}]", v.iter().map(|b| b.to_string()).collect::<Vec<_>>().join(", ")));
}
marker()
}
_ => row.try_get::<String, _>(index).map(Value::Text).unwrap_or_else(|_| marker()),
}
}