
CREATE TABLE book (
	"Book_ID" INTEGER, 
	"Title" TEXT, 
	"Issues" REAL, 
	"Writer" TEXT, 
	PRIMARY KEY ("Book_ID")
)


CREATE TABLE publication (
	"Publication_ID" INTEGER, 
	"Book_ID" INTEGER, 
	"Publisher" TEXT, 
	"Publication_Date" TEXT, 
	"Price" REAL, 
	PRIMARY KEY ("Publication_ID"), 
	FOREIGN KEY("Book_ID") REFERENCES book ("Book_ID")
)

CREATE TABLE book (
	"Book_ID" INTEGER, 
	"Title" TEXT, 
	"Issues" REAL, 
	"Writer" TEXT, 
	PRIMARY KEY ("Book_ID")
)

/*
2 rows from book table:
Book_ID	Title	Issues	Writer
1	The Black Lamb	6.0	Timothy Truman
2	Bloody Mary	4.0	Garth Ennis
*/


CREATE TABLE publication (
	"Publication_ID" INTEGER, 
	"Book_ID" INTEGER, 
	"Publisher" TEXT, 
	"Publication_Date" TEXT, 
	"Price" REAL, 
	PRIMARY KEY ("Publication_ID"), 
	FOREIGN KEY("Book_ID") REFERENCES book ("Book_ID")
)

/*
2 rows from publication table:
Publication_ID	Book_ID	Publisher	Publication_Date	Price
1	1	Pearson	August 2008	15000000.0
2	3	Thomson Reuters	March 2008	6000000.0
*/
What is the number of distinct publication dates?
SELECT COUNT (DISTINCT Publication_Date) FROM publication
[{'COUNT (DISTINCT Publication_Date)': 6}]