Database on David Lang

Using dynamic SQL query in Redshift database

Thu, 16 Nov 2023 00:00:00 +0000

While working with a client, we had a requirement to perform bulk insert/update using Retool table and Redshift database. For this situation, We had to loop through the table records and execute a dynamic SQL query in Redshift.

Redshift database supports execution of dynamic SQL with the help of Prepared Statements or Stored Procedures.

Prepared Statements

We use prepared statements when we want to execute dynamic SQL queries directly without a stored procedure. When a prepared statement is executed, the SQL statement is parsed, rewritten, and planned. We then EXECUTE the prepared statement.

Prisma ORM: Modern Database Access in Node.js

Tue, 07 Dec 2021 00:00:00 +0000

Prisma provides type-safe database access, migrations, and a visual data browser-popular in TypeScript full stack projects.

Schema Definition

model User {
  id        String   @id @default(cuid())
  email     String   @unique
  posts     Post[]
  createdAt DateTime @default(now())
}

model Post {
  id       String @id @default(cuid())
  title    String
  author   User   @relation(fields: [authorId], references: [id])
  authorId String
}

Queries

const users = await prisma.user.findMany({
  include: { posts: true },
  where: { email: { contains: '@company.com' } },
});

Migrations

npx prisma migrate dev applies schema changes in development. Use prisma generate after schema edits to refresh the client.

MongoDB Best Practices: Schema Design and Indexing

Mon, 25 Oct 2021 00:00:00 +0000

MongoDB’s flexible documents are powerful-but schema design still matters for performance and maintainability.

Embedding vs Referencing

Embed when data is read together and has a one-to-few relationship (user preferences inside a user doc). Reference when data grows unbounded or is shared (comments on posts).

Indexing

db.orders.createIndex({ customerId: 1, createdAt: -1 });

Compound indexes support queries that filter and sort on the same fields. Use .explain() to verify index usage.

Validation and Migrations

Use JSON Schema validation at the collection level. Version documents with a schemaVersion field for gradual migrations.

PostgreSQL vs MySQL: Choosing the Right Database

Mon, 10 Aug 2020 00:00:00 +0000

Relational databases remain the backbone of most full stack applications. PostgreSQL and MySQL are the two most common choices-each excels in different scenarios.

PostgreSQL Strengths

PostgreSQL offers advanced types (JSONB, arrays), full-text search, robust concurrency (MVCC), and extensions like PostGIS. It is the default choice for complex queries, analytics-heavy apps, and strict data integrity.

MySQL Strengths

MySQL (and MariaDB) are widely hosted, familiar to many teams, and perform well for read-heavy web workloads. Managed offerings are plentiful and often slightly cheaper at small scale.