Files
bun-sqlite/dist/lib/schema/update-table.js
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89 lines
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JavaScript

import { sqlQuoteIdent as q } from "../../utils/sql-safe";
import buildCreateTableSql from "./build-create-table-sql";
import checkIfTableExists from "./check-if-table-exists";
import getTableColumns from "./get-table-columns";
import recordSchemaChange from "./record-schema-change";
import resolveTable from "./resolve-table";
/**
* # Update an existing table
* @description SQLite has limited ALTER TABLE support, so a changed table is
* rebuilt: create a temp table with the new schema, copy the data over,
* drop the old table and rename the temp table. Unchanged tables are left
* alone.
*/
export default function updateTable(params) {
const { db, db_schema, table } = params;
if (table.isVector) {
recreateVectorTable(params);
return;
}
/**
* SQLite keeps the `CREATE TABLE` text (with the renamed table name), so
* an identical statement means the table already matches the schema.
*/
const current = db
.query(`SELECT sql FROM sqlite_master WHERE type='table' AND name=?`)
.get(table.tableName);
if (current?.sql === buildCreateTableSql({ db_schema, table })) {
return;
}
const tempTableName = `${table.tableName}_temp_${Date.now()}`;
// Columns are matched by name only: SQLite converts values to the new
// column affinity on copy, so a type change keeps the data instead of
// silently dropping the column.
const existingColumns = getTableColumns({ db, table_name: table.tableName });
const schemaColumns = resolveTable({ table, db_schema }).fields.map((f) => f.fieldName);
const columnsToKeep = existingColumns
.map((c) => c.name)
.filter((name) => schemaColumns.includes(name));
const columnsToDrop = existingColumns
.map((c) => c.name)
.filter((name) => !schemaColumns.includes(name));
recordSchemaChange(params, {
description: `Rebuild table "${table.tableName}"`,
});
for (const column of columnsToDrop) {
recordSchemaChange(params, {
description: `Drop column "${table.tableName}"."${column}"`,
destructive: true,
});
}
// Create temp table with new schema
db.run(buildCreateTableSql({
db_schema,
table: { ...table, tableName: tempTableName },
}));
// Copy data if there are common columns
if (columnsToKeep.length > 0) {
const columnList = columnsToKeep.map(q).join(", ");
db.run(`INSERT INTO ${q(tempTableName)} (${columnList}) SELECT ${columnList} FROM ${q(table.tableName)}`);
}
db.run(`DROP TABLE ${q(table.tableName)}`);
db.run(`ALTER TABLE ${q(tempTableName)} RENAME TO ${q(table.tableName)}`);
}
/**
* Vector tables are only rebuilt when `recreate_vector_table` is set.
*/
function recreateVectorTable(params) {
const { db, db_schema, table, recreate_vector_table } = params;
if (!recreate_vector_table) {
return;
}
recordSchemaChange(params, {
description: `Recreate vector table "${table.tableName}"`,
});
let existingRows = [];
if (checkIfTableExists({ db, table_name: table.tableName })) {
existingRows = db
.query(`SELECT * FROM ${q(table.tableName)}`)
.all();
db.run(`DROP TABLE ${q(table.tableName)}`);
}
db.run(buildCreateTableSql({ db_schema, table }));
for (const row of existingRows) {
const columns = Object.keys(row);
const placeholders = columns.map(() => "?").join(", ");
db.run(`INSERT INTO ${q(table.tableName)} (${columns.map(q).join(", ")}) VALUES (${placeholders})`, Object.values(row));
}
}