SQLite

**
** <blockquote>
** <table border="1">
** <tr><th> Internal<br>Type <th> Requested<br>Type <th>  Conversion
**
** <tr><td>  NULL    <td> INTEGER   <td> Result is 0
** <tr><td>  NULL    <td>  FLOAT    <td> Result is 0.0
** <tr><td>  NULL    <td>   TEXT    <td> Result is a NULL pointer
** <tr><td>  NULL    <td>   BLOB    <td> Result is a NULL pointer
** <tr><td> INTEGER  <td>  FLOAT    <td> Convert from integer to float
** <tr><td> INTEGER  <td>   TEXT    <td> ASCII rendering of the integer
** <tr><td> INTEGER  <td>   BLOB    <td> Same as INTEGER->TEXT
** <tr><td>  FLOAT   <td> INTEGER   <td> [CAST] to INTEGER
** <tr><td>  FLOAT   <td>   TEXT    <td> ASCII rendering of the float
** <tr><td>  FLOAT   <td>   BLOB    <td> [CAST] to BLOB
** <tr><td>  TEXT    <td> INTEGER   <td> [CAST] to INTEGER
** <tr><td>  TEXT    <td>  FLOAT    <td> [CAST] to REAL
** <tr><td>  TEXT    <td>   BLOB    <td> No change
** <tr><td>  BLOB    <td> INTEGER   <td> [CAST] to INTEGER
** <tr><td>  BLOB    <td>  FLOAT    <td> [CAST] to REAL
** <tr><td>  BLOB    <td>   TEXT    <td> Add a zero terminator if needed
** </table>
** </blockquote>)^
**
** The table above makes reference to standard C library functions atoi()
** and atof().  SQLite does not really use these functions.  It has its
** own equivalent internal routines.  The atoi() and atof() names are

# Tests for statements regarding constraints (PRIMARY KEY, UNIQUE, NOT 
# NULL and CHECK constraints).
#

# EVIDENCE-OF: R-52382-54248 Each table in SQLite may have at most one
# PRIMARY KEY.
# 
# EVIDENCE-OF: R-31826-01813 An error is raised if more than one PRIMARY
# KEY clause appears in a CREATE TABLE statement.
#
#     To test the two above, show that zero primary keys is Ok, one primary
#     key is Ok, and two or more primary keys is an error.
#
drop_all_tables
do_createtable_tests 4.1.1 {

} {R1 R2 R3}
do_test e_expr-26.1.6 { set ::evalcount } {5}


#-------------------------------------------------------------------------
# Test statements related to CAST expressions.
#
# EVIDENCE-OF: R-20854-17109 A CAST conversion is similar to the
# conversion that takes place when a column affinity is applied to a
# value except that with the CAST operator the conversion always takes
# place even if the conversion lossy and irreversible, whereas column
# affinity only changes the data type of a value if the change is
# lossless and reversible.
#
do_execsql_test e_expr-27.1.1 {
  CREATE TABLE t3(a TEXT, b REAL, c INTEGER);
  INSERT INTO t3 VALUES(X'555655', '1.23abc', 4.5);
  SELECT typeof(a), a, typeof(b), b, typeof(c), c FROM t3;
} {blob UVU text 1.23abc real 4.5}
do_execsql_test e_expr-27.1.2 {

# EVIDENCE-OF: R-43164-44276 If there is no prefix that can be
# interpreted as an integer number, the result of the conversion is 0.
#
do_expr_test e_expr-30.4.1 { CAST('' AS INTEGER) } integer 0
do_expr_test e_expr-30.4.2 { CAST('not a number' AS INTEGER) } integer 0
do_expr_test e_expr-30.4.3 { CAST('XXI' AS INTEGER) } integer 0

# EVIDENCE-OF: R-02752-50091 A cast of a REAL value into an INTEGER
# results in the integer between the REAL value and zero that is closest
# to the REAL value.
#
do_expr_test e_expr-31.1.1 { CAST(3.14159 AS INTEGER) } integer 3
do_expr_test e_expr-31.1.2 { CAST(1.99999 AS INTEGER) } integer 1
do_expr_test e_expr-31.1.3 { CAST(-1.99999 AS INTEGER) } integer -1
do_expr_test e_expr-31.1.4 { CAST(-0.99999 AS INTEGER) } integer 0

# EVIDENCE-OF: R-51517-40824 If a REAL is greater than the greatest