Rounding off to two decimal places in SQL

Present it right: The CAST function

CAST stars in this type converting show, dialing specific precision (up to 38) and scale:

-- Be precise, or be gone!
SELECT CAST(column AS NUMERIC(precision, 2)) FROM table;
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Here precision defines the total digit count, while scale is your personal DJ for digits after the decimal. For a wider range, consider NUMERIC(18,2) as your precision knight in the shinning armor.

FLOATing in precision with ROUND

When dealing with float-type data, precision is on the line. Always round before casting:

-- Round o' Float, you're next!
SELECT CAST(ROUND(float_column, 2) AS FLOAT) FROM table;
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FLOAT, being an approximate data type, can sometimes act strange. If you desire exact outcomes, then NUMERIC or DECIMAL are your soulmates.

SQL Server's inbuilt stylist: FORMAT

SQL Server 2012 or newer have FORMAT(), the inbuilt stylist for data:

-- One-liner beauty salon!
SELECT FORMAT(column, 'N2') FROM table;
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One simple line rounds and adds a consistent two decimal point display - the epitome of concise elegance.

Entertaining time-conversion with CAST

Converting minutes into hour, with a dab of CAST, follows the SQL Tao of precision:

-- Behold, the mathemagician!
SELECT CAST((minutes_column / 60.0) AS NUMERIC(16,2)) FROM table;
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By dividing by 60.0 (not just 60), we avoid the gruesome wrath of integer division.

Introduction to SQL aristocracy: Variables

Unravel the potential of declared variables in complex queries:

-- Welcome to the SQL Aristocracy!;
DECLARE @ValueToRound NUMERIC(16,4) = column_name;
SELECT CAST(ROUND(@ValueToRound, 2) AS NUMERIC(16,2));
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Even Shakespeare would approve of this decl(i)aration.

Corner cases: SQL's quirky precision actors

Streamline precision and scale with these pro moves:

• Save yourself from the embarrassment of overflow errors. Count x <= 38 in NUMERIC(x,2).
• Review CAST settings with a fine-toothed comb. Leave no unwanted rounding undiscovered.
• The fun-loving FLOAT type might lure you into rounding errors. Keep it real with DECIMAL for monetary values.

The DBMS detour: SQL Server, Oracle, PostgreSQL and others

This syntax specifically greets SQL Server inhabitants. For those in the kingdom of Oracle, PostgreSQL, MySQL and the like, there may be minor changes:

-- When in Rome..
SELECT ROUND(column_name, 2) FROM table; 
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Display beauty: The CAST and ROUND combo

Let layout speak louder than words. Combine ROUND() and CAST() for a beautiful data display:

-- That's some high fashion data!;
SELECT CAST(ROUND(column, 2) AS NUMERIC(16,2)) FROM table;
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