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目录

Conditional Functions

# StreamSQL Conditional Functions

Conditional functions are used for conditional judgment and value selection.

# IF_NULL - Null Handling Function

Syntax: if_null(value, default_value)
Description: If the value is NULL, returns the default value; otherwise returns the original value.

# COALESCE - Coalesce Function

Syntax: coalesce(value1, value2, ...)
Description: Returns the first non-NULL value.

# NULL_IF - Null Conversion Function

Syntax: null_if(value1, value2)
Description: If the two values are equal, returns NULL; otherwise returns the first value.

# GREATEST - Greatest Function

Syntax: greatest(value1, value2, ...)
Description: Returns the maximum value among the parameters.

# LEAST - Least Function

Syntax: least(value1, value2, ...)
Description: Returns the minimum value among the parameters.

# CASE_WHEN - Conditional Branch Function

Syntax: case_when(condition, value_if_true, value_if_false)
Description: Returns different values based on the condition.

# 📚 Related Documentation

  • Type Check Functions - Learn detailed usage of type check functions
  • Multi-row Functions - Learn detailed usage of multi-row functions
  • SQL Reference - View complete SQL syntax reference
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Last Updated: 2025/08/05, 02:24:31
Type Check Functions
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