How to fix Cannot coerce in PostgreSQL

-- Error example: cannot cast type text to integer
SELECT * FROM users WHERE id = '123'; -- This fails if id is integer

-- For tables:
\d table_name

-- For functions:
\df+ function_name

-- For specific column info:
SELECT column_name, data_type FROM information_schema.columns
WHERE table_name = 'your_table';

-- Cast string to integer
SELECT * FROM users WHERE id = '123'::integer;

-- Cast integer to text for comparison
SELECT * FROM logs WHERE user_id::text = '456';

-- Cast in JOIN conditions
SELECT * FROM orders o
JOIN customers c ON o.customer_id::bigint = c.id::bigint;

-- Equivalent to the :: syntax above
SELECT * FROM users WHERE id = CAST('123' AS INTEGER);

SELECT * FROM logs WHERE CAST(user_id AS TEXT) = '456';

INSERT INTO numbers(val) VALUES (CAST('789' AS INTEGER));

-- Wrong: Inserting text into integer column
INSERT INTO products(price) VALUES ('99.99');

-- Correct: Cast to proper numeric type
INSERT INTO products(price) VALUES ('99.99'::numeric);
INSERT INTO products(price) VALUES (CAST('99.99' AS NUMERIC));

-- For VARCHAR columns expecting numbers
INSERT INTO data(code) VALUES (123::varchar);

-- Alter column type if many casts are needed
ALTER TABLE users ALTER COLUMN id TYPE BIGINT;

-- Or convert existing data before altering
ALTER TABLE logs ALTER COLUMN timestamp TYPE TIMESTAMP USING timestamp::TIMESTAMP;

-- Verify foreign key types match:
-- If orders.customer_id is INT but customers.id is BIGINT, align them
ALTER TABLE orders ALTER COLUMN customer_id TYPE BIGINT;