I'm very honored to be speaking at Dev Day 2014 in Krakow this September!
A nun of the Elephant's Footprint Clan sat cross-legged upon her desk, quietly contemplating an Entity-Relationship diagram on her whiteboard.
The Java master* observed this and approached.
The God of the Silence Between Words was already in the room.
The nun pointed to the diagram. “This column named complete is declared to hold an integer. An examination of the data shows that it contains two unique values: zero and one. I presume that the zero indicates falsehood, and the one, truth.”
Said the master: “Only an initiate can say what is counted by these numbers.”
Said the God of the Silence Between Words: “The presence of a single zero implies the existence of a one to count it, and then a two to count both, and likewise to infinity. Did the universe spring thusly from the shell of a serpent’s egg?”
The nun raised the first two fingers on her right hand. “I have considered storing a two in some random row, merely to observe the effect on the application.”
Said the master: “You seek to determine whether truth is regarded as the presence of a one, or the absence of a zero.”
Said the God of the Silence Between Words: “The absence of a zero implies a presence. The presence of a zero implies an absence. When the serpent devours its tail up to the tip of its tongue, then what remains?”
The nun pressed her index finger to her chin. “The column also allows nulls. If the column asks a question, convention dictates that a null represents an unknown answer.”
Said the master: “This null is either the shrewd pause that precedes a lie, or the gentle hush before the revelation of truth. Its quality rests entirely in what it will become. Only when it ceases to exist may we understand what it was.”
Said the God of the Silence Between Words: “The ghost borrows the form of the departed. Yet what shape may we assign the spirit of the yet-unborn?”
The nun steepled her fingers. “Before the application queries the database, the value of this column is unknown. Afterwards, any null in this column will be represented intentionally as a null Boolean. The value is then simultaneously known and unknown.”
Said the master: “We have learned only that we have learned nothing, yet this is the root of wisdom.”
Said the God of the Silence Between Words: “The sage and the fool go to their graves alike in this respect: both believe the sage to be a fool. Where, then, may wisdom be found?”
The nun folded her hands in her lap. “The null SQL integer, persisted, becomes the null Boolean in fleeting memory. Two nothings, of wholly different natures. How can absences be inequal?”
The master nodded.
The God of the Silence Between Words raised an eyebrow.
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