Query the database
This guide explains how to connect to the database (either SQLite or Postgres) and run direct SQL queries.
SQLite
Database files
During local development, Ponder uses SQLite database files located in the .ponder/sqlite
directory.
- public.db
- ponder_sync.db
public.db
: Contains a live indexed table for each table inponder.schema.ts
. It's safe to read data from this database during local development and testing.ponder_sync.db
: Contains raw blockchain data that has been cached locally.
Note: SQLite sometimes creates a -shm
and -wal
file alongside database files. Do not modify or delete them.
Connect with sqlite3
To get oriented, connect to the SQLite database using sqlite3
(installation guide) and run a few test queries. For the queries that follow, assume there is a Ponder app running with this ponder.schema.ts
.
Example ponder.schema.ts
ponder.schema.ts
import { createSchema } from "@ponder/core";
export default createSchema((p) => ({
Account: p.createTable({
id: p.hex(),
balance: p.bigint(),
isOwner: p.boolean(),
}),
TransferEvent: p.createTable({
id: p.string(),
amount: p.bigint(),
timestamp: p.int(),
fromId: p.hex().references("Account.id"),
toId: p.hex().references("Account.id"),
}),
}));
File path
Connect to the database by passing a file path to sqlite3
.
# From your project root
sqlite3 .ponder/sqlite/public.db
# Or, an absolute path
sqlite3 /workspace/my-app/.ponder/sqlite/public.db
Once connected, you'll see a sqlite>
prompt.
SQLite version 3.37.0 2021-12-09 01:34:53
Enter ".help" for usage hints.
sqlite>
Display tables
Use the .tables
command to list all tables in the database.
.tables
sqlite> .tables
Account TransferEvent
Display schema
Use the .schema
command to print CREATE TABLE statements for each table.
.schema
sqlite> .schema
CREATE TABLE IF NOT EXISTS "Account" ("id" blob not null primary key, "balance" varchar(79) not null, "isOwner" integer not null);
CREATE TABLE IF NOT EXISTS "TransferEvent" ("id" text not null primary key, "amount" varchar(79) not null, "timestamp" integer not null, "fromId" blob not null, "toId" blob not null);
Select rows
First, adjust some settings to make sqlite3
results easier to read.
.headers ON
.mode columns
Select a few TransferEvent
rows.
SELECT * FROM TransferEvent LIMIT 3;
sqlite> SELECT * FROM TransferEvent LIMIT 3;
id amount timestamp fromId toId
------------------------------------------------------------------------ ------------------------------------------------------------------------------- ---------- ------ -----------------
0x3783f4bba84605ffa296db73fcbdb010caf0542b460035d7bed4129db02fd0e2-0x1a5 0000000000000000000000000000000000000000000000000000000010000000000000000000000 1630539461 ???\???<0???%d??
0xd8612316d81529ccc73faf26318594a50cc4dffbbe0553ccf7a14a514f889fff-0xd5 0000000000000000000000000000000000000000000000000000000010000000000000000000000 1630541604 ??ÉhP/w?~?mrrW???R
0x1605392466b635d4eb1552f66832ade6da40a904b00566502b4ba3bdb08ab6a8-0x1a3 0000000000000000000000000000000000000000000000000000000010000000000000000000000 1630541770 ?7g?ʲo&??<}?x
Clearly, raw sqlite3
results are not easy on the eyes. The balance
column is encoded as VARCHAR(79)
, and the toId
column contains hex values encoded as BLOB
. See the column types section for more details.
Aggregate data
Select all Account
records that have received more than 10 transfers.
SELECT *
FROM Account
WHERE id IN (
SELECT toId
FROM TransferEvent
GROUP BY toId
HAVING COUNT(*) > 10
)
LIMIT 3;
sqlite> SELECT * FROM Account WHERE id IN ( SELECT toId FROM TransferEvent GROUP BY toId HAVING COUNT(*) > 10 ) LIMIT 3;
id balance isOwner
---------------- ------------------------------------------------------------------------------- -------
.?Ëź???(?4[W? 0000000000000000000000000000000000000000000000000000000140000000000000000000000 0
y?D???ꎇ ?[?> 0000000000000000000000000000000000000000000000000000000290000000000000000000000 0
3?ek{3F4oi}??B? 0000000000000000000000000000000000000000000000000000000230000000000000000000000 0
Column types
These are the SQLite data types used by each ponder.schema.ts
column type.
Schema column type | SQLite column type | Notes |
---|---|---|
p.string() | TEXT | |
p.hex() | BLOB | |
p.int() | INTEGER | |
p.bigint() | VARCHAR(79) | Supports EVM uint256 and int256 (custom encoding) |
p.float() | REAL | |
p.boolean() | INTEGER | 0 is false , 1 is true |
p.json() | JSONB |
SQLite bigint encoding
SQLite does not natively support integers larger than 8 bytes. To safely store and compare large integers (such as 32-byte EVM uint256
values) in SQLite, we designed an encoding that uses VARCHAR(79)
and takes advantage of SQLite's native lexicographic sort. Here is the reference implementation used by Ponder internally.
Indexes
To create indexes on specific columns, use the p.index()
function in ponder.schema.ts
Do not manually construct database indexes. Read more.
Postgres
Database schema
By default, Ponder uses the public
database schema for indexed data, one table for each table in ponder.schema.ts
. To use a different schema, set the schema
option in ponder.config.ts
.
import { createConfig } from "@ponder/core"
export default createConfig({
database: {
kind: "postgres",
schema: "dev", // Defaults to "public"
},
});
Like with SQLite, Ponder also uses the ponder_sync
Postgres database schemas for cached RPC data.
Connect using psql
To get oriented, connect to the database using psql
(installation guide) and run a few test queries. For the queries that follow, assume there is a Ponder app running with this ponder.schema.ts
.
Example ponder.schema.ts
ponder.schema.ts
import { createSchema } from "@ponder/core";
export default createSchema((p) => ({
Account: p.createTable({
id: p.hex(),
balance: p.bigint(),
isOwner: p.boolean(),
}),
TransferEvent: p.createTable({
id: p.string(),
amount: p.bigint(),
timestamp: p.int(),
fromId: p.hex().references("Account.id"),
toId: p.hex().references("Account.id"),
}),
}));
Connection string
Connect using the same connection string that your Ponder app uses (the DATABASE_URL
environment variable).
psql 'postgresql://username:password@localhost:5432/your_database'
Display tables
Use the \dt
command to list all tables in the public
schema.
\dt
username=# \dt
List of relations
Schema | Name | Type | Owner
--------+---------------+-------+----------
public | Account | table | username
public | TransferEvent | table | username
(4 rows)
If you're using a schema other than public
, you'll need to include a pattern:
\dt another_schema.*
Select rows
Select a few Account
rows.
SELECT * FROM "Account" LIMIT 5;
username=# SELECT * FROM "Account" LIMIT 5;
id | balance | isOwner
--------------------------------------------+-------------------------+---------
\xf73fe15cfb88ea3c7f301f16ade3c02564aca407 | 10000000000000000000000 | 0
\xb0659bc97ed61b37d6b140f3e12a41d471781714 | 20000000000000000000000 | 0
\x52932f5b2767d917c3134140168f2176c94e8b2c | 10000000000000000000000 | 0
\xfb7ca75b3ce099120602b5ab7104cff030ee43f8 | 0 | 0
\x9ccc6c5a9d25429f55ad9af6363c1c4f16b179ad | 7000000000000000000000 | 0
(5 rows)
Note that the id
column uses the p.hex()
column type in ponder.schema.ts
, which corresponds to the Postgres BYTEA
data type. See the column types section for more details.
Aggregate data
Find the total number of transfers sent to each account.
SELECT "toId", COUNT(*) AS transfer_count
FROM "TransferEvent"
GROUP BY "toId"
ORDER BY transfer_count DESC
LIMIT 5;
username=# SELECT "toId", COUNT(*) AS transfer_count FROM "TransferEvent" GROUP BY "toId" ORDER BY transfer_count DESC LIMIT 5;
toId | transfer_count
--------------------------------------------+----------------
\x5d752f322befb038991579972e912b02f61a3dda | 2342
\x1337f7970e8399ccbc625647fce58a9dada5aa66 | 313
\x9726041047644626468922598128349778349982 | 306
\x27239549dd40e1d60f5b80b0c4196923745b1fd2 | 256
\x450638daf0caedbdd9f8cb4a41fa1b24788b123e | 238
(5 rows)
Column types
These are the Postgres data types used by each ponder.schema.ts
column type.
Schema column type | Postgres column type | Notes |
---|---|---|
p.string() | TEXT | |
p.hex() | BYTEA | |
p.int() | INTEGER | |
p.bigint() | NUMERIC(78, 0) | Supports EVM uint256 and int256 |
p.float() | FLOAT8 /DOUBLE | |
p.boolean() | INTEGER | 0 is false , 1 is true |
p.json() | JSONB |
Indexes
To create indexes on specific columns, use the p.index()
function in ponder.schema.ts
Do not manually construct database indexes. Read more.