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sqlite3.h - SQLite Embedded Database

Category: 📂 sql/ (Third-Party Ecosystem) Header: <sqlite3.h> Scope: Embedded SQL Database

The sqlite3.h header is the interface for SQLite, a C-language library that implements a small, fast, self-contained, high-reliability, full-featured, SQL database engine.

Facilities Overview

Facility Category Key Symbols Description
Database Mgmt sqlite3_open, sqlite3_close Opening and closing database files.
Execution sqlite3_exec Executing one or more SQL statements directly.
Prepared Stmts sqlite3_prepare_v2, sqlite3_step Compiling SQL and iterating over results.
Column Access sqlite3_column_text, sqlite3_column_int Retrieving data from a query row.
Error Handling sqlite3_errmsg Retrieving error description strings.

Types & Variables

sqlite3

typedef struct sqlite3 sqlite3;

An opaque handle representing a database connection.

sqlite3_stmt

typedef struct sqlite3_stmt sqlite3_stmt;

An opaque handle representing a single compiled SQL statement.

Functions

Connection Management

sqlite3_open

int sqlite3_open(const char *filename, sqlite3 **ppDb)

Opens a new connection to a SQLite database.

Returns: SQLITE_OK on success. On failure, returns an error code (and *ppDb may still be allocated, requiring close).

Example 
#include <sqlite3.h>
#include <stdio.h>

int main(void) {
    sqlite3 *db;
    int rc = sqlite3_open(":memory:", &db);
    
    if (rc != SQLITE_OK) {
        fprintf(stderr, "Cannot open database: %s\n", sqlite3_errmsg(db));
        sqlite3_close(db);
        return 1;
    }
    
    printf("Database opened successfully.\n");
    sqlite3_close(db);
    return 0;
}

sqlite3_close

int sqlite3_close(sqlite3 *db)

Closes a database connection.

Returns: SQLITE_OK on success.

Direct Execution

sqlite3_exec

int sqlite3_exec(sqlite3 *db, const char *sql, int (*callback)(void*,int,char**,char**), void *arg, char **errmsg)

Compiles and executes one or more SQL statements (often used for schema creation).

Returns: SQLITE_OK on success.

Prepared Statements

sqlite3_prepare_v2

int sqlite3_prepare_v2(sqlite3 *db, const char *zSql, int nByte, sqlite3_stmt **ppStmt, const char **pzTail)

Compiles a SQL statement into a byte-code program.

Returns: SQLITE_OK on success.

sqlite3_step

int sqlite3_step(sqlite3_stmt *pStmt)

Evaluates a prepared statement.

Returns:

  • SQLITE_ROW: A row of data is ready.
  • SQLITE_DONE: Execution completed.
  • Other error codes.

sqlite3_finalize

int sqlite3_finalize(sqlite3_stmt *pStmt)

Destroys a prepared statement object.

Returns: SQLITE_OK on success.

Column Access

sqlite3_column_text

const unsigned char *sqlite3_column_text(sqlite3_stmt *pStmt, int iCol)

Returns the text value of the column iCol (0-indexed) in the current row.

Returns: Pointer to the text string, or NULL.

sqlite3_column_int

int sqlite3_column_int(sqlite3_stmt *pStmt, int iCol)

Returns the integer value of the column iCol.

Returns: The integer value.

Error Handling

sqlite3_errmsg

const char *sqlite3_errmsg(sqlite3 *db)

Returns a description of the error that caused the most recent call to fail.

Returns: A pointer to a static error string.