Files
turso/packages/turso-serverless/src/statement.ts
2025-08-19 16:35:44 +03:00

272 lines
8.6 KiB
TypeScript

import {
decodeValue,
type CursorEntry,
type Column
} from './protocol.js';
import { Session, type SessionConfig } from './session.js';
import { DatabaseError } from './error.js';
/**
* A prepared SQL statement that can be executed in multiple ways.
*
* Each statement has its own session to avoid conflicts during concurrent execution.
* Provides three execution modes:
* - `get(args?)`: Returns the first row or null
* - `all(args?)`: Returns all rows as an array
* - `iterate(args?)`: Returns an async iterator for streaming results
*/
export class Statement {
private session: Session;
private sql: string;
private presentationMode: 'expanded' | 'raw' | 'pluck' = 'expanded';
private safeIntegerMode: boolean = false;
private columnMetadata: Column[];
constructor(sessionConfig: SessionConfig, sql: string, columns?: Column[]) {
this.session = new Session(sessionConfig);
this.sql = sql;
this.columnMetadata = columns || [];
}
/**
* Enable raw mode to return arrays instead of objects.
*
* @param raw Enable or disable raw mode. If you don't pass the parameter, raw mode is enabled.
* @returns This statement instance for chaining
*
* @example
* ```typescript
* const stmt = client.prepare("SELECT * FROM users WHERE id = ?");
* const row = await stmt.raw().get([1]);
* console.log(row); // [1, "Alice", "alice@example.org"]
* ```
*/
raw(raw?: boolean): Statement {
this.presentationMode = raw === false ? 'expanded' : 'raw';
return this;
}
/**
* Enable pluck mode to return only the first column value from each row.
*
* @param pluck Enable or disable pluck mode. If you don't pass the parameter, pluck mode is enabled.
* @returns This statement instance for chaining
*
* @example
* ```typescript
* const stmt = client.prepare("SELECT id FROM users");
* const ids = await stmt.pluck().all();
* console.log(ids); // [1, 2, 3, ...]
* ```
*/
pluck(pluck?: boolean): Statement {
this.presentationMode = pluck === false ? 'expanded' : 'pluck';
return this;
}
/**
* Sets safe integers mode for this statement.
*
* @param toggle Whether to use safe integers. If you don't pass the parameter, safe integers mode is enabled.
* @returns This statement instance for chaining
*/
safeIntegers(toggle?: boolean): Statement {
this.safeIntegerMode = toggle === false ? false : true;
return this;
}
/**
* Get column information for this statement.
*
* @returns Array of column metadata objects matching the native bindings format
*
* @example
* ```typescript
* const stmt = await client.prepare("SELECT id, name, email FROM users");
* const columns = stmt.columns();
* console.log(columns); // [{ name: 'id', type: 'INTEGER', column: null, database: null, table: null }, ...]
* ```
*/
columns(): any[] {
return this.columnMetadata.map(col => ({
name: col.name,
type: col.decltype
}));
}
/**
* Executes the prepared statement.
*
* @param args - Optional array of parameter values or object with named parameters
* @returns Promise resolving to the result of the statement
*
* @example
* ```typescript
* const stmt = client.prepare("INSERT INTO users (name, email) VALUES (?, ?)");
* const result = await stmt.run(['John Doe', 'john.doe@example.com']);
* console.log(`Inserted user with ID ${result.lastInsertRowid}`);
* ```
*/
async run(args?: any): Promise<any> {
const normalizedArgs = this.normalizeArgs(args);
const result = await this.session.execute(this.sql, normalizedArgs, this.safeIntegerMode);
return { changes: result.rowsAffected, lastInsertRowid: result.lastInsertRowid };
}
/**
* Execute the statement and return the first row.
*
* @param args - Optional array of parameter values or object with named parameters
* @returns Promise resolving to the first row or undefined if no results
*
* @example
* ```typescript
* const stmt = client.prepare("SELECT * FROM users WHERE id = ?");
* const user = await stmt.get([123]);
* if (user) {
* console.log(user.name);
* }
* ```
*/
async get(args?: any): Promise<any> {
const normalizedArgs = this.normalizeArgs(args);
const result = await this.session.execute(this.sql, normalizedArgs, this.safeIntegerMode);
const row = result.rows[0];
if (!row) {
return undefined;
}
if (this.presentationMode === 'pluck') {
// In pluck mode, return only the first column value
return row[0];
}
if (this.presentationMode === 'raw') {
// In raw mode, return the row as a plain array (it already is one)
// The row object is already an array with column properties added
return [...row];
}
// In expanded mode, convert to plain object with named properties
const obj: any = {};
result.columns.forEach((col: string, i: number) => {
obj[col] = row[i];
});
return obj;
}
/**
* Execute the statement and return all rows.
*
* @param args - Optional array of parameter values or object with named parameters
* @returns Promise resolving to an array of all result rows
*
* @example
* ```typescript
* const stmt = client.prepare("SELECT * FROM users WHERE active = ?");
* const activeUsers = await stmt.all([true]);
* console.log(`Found ${activeUsers.length} active users`);
* ```
*/
async all(args?: any): Promise<any[]> {
const normalizedArgs = this.normalizeArgs(args);
const result = await this.session.execute(this.sql, normalizedArgs, this.safeIntegerMode);
if (this.presentationMode === 'pluck') {
// In pluck mode, return only the first column value from each row
return result.rows.map((row: any) => row[0]);
}
if (this.presentationMode === 'raw') {
return result.rows.map((row: any) => [...row]);
}
// In expanded mode, convert rows to plain objects with named properties
return result.rows.map((row: any) => {
const obj: any = {};
result.columns.forEach((col: string, i: number) => {
obj[col] = row[i];
});
return obj;
});
}
/**
* Execute the statement and return an async iterator for streaming results.
*
* This method provides memory-efficient processing of large result sets
* by streaming rows one at a time instead of loading everything into memory.
*
* @param args - Optional array of parameter values or object with named parameters
* @returns AsyncGenerator that yields individual rows
*
* @example
* ```typescript
* const stmt = client.prepare("SELECT * FROM large_table WHERE category = ?");
* for await (const row of stmt.iterate(['electronics'])) {
* // Process each row individually
* console.log(row.id, row.name);
* }
* ```
*/
async *iterate(args?: any): AsyncGenerator<any> {
const normalizedArgs = this.normalizeArgs(args);
const { response, entries } = await this.session.executeRaw(this.sql, normalizedArgs);
let columns: string[] = [];
for await (const entry of entries) {
switch (entry.type) {
case 'step_begin':
if (entry.cols) {
columns = entry.cols.map(col => col.name);
}
break;
case 'row':
if (entry.row) {
const decodedRow = entry.row.map(value => decodeValue(value, this.safeIntegerMode));
if (this.presentationMode === 'pluck') {
// In pluck mode, yield only the first column value
yield decodedRow[0];
} else if (this.presentationMode === 'raw') {
// In raw mode, yield arrays of values
yield decodedRow;
} else {
const rowObject = this.session.createRowObject(decodedRow, columns);
yield rowObject;
}
}
break;
case 'step_error':
case 'error':
throw new DatabaseError(entry.error?.message || 'SQL execution failed');
}
}
}
/**
* Normalize arguments to handle both single values and arrays.
* Matches the behavior of the native bindings.
*/
private normalizeArgs(args: any): any[] | Record<string, any> {
// No arguments provided
if (args === undefined) {
return [];
}
// If it's an array, return as-is
if (Array.isArray(args)) {
return args;
}
// Check if it's a plain object (for named parameters)
if (args !== null && typeof args === 'object' && args.constructor === Object) {
return args;
}
// Single value - wrap in array
return [args];
}
}